Negligence - Failure to prevent third-party harm

Learning Outcomes

This article outlines the general principles relating to liability in negligence for failing to act (omissions) and for harm caused by the actions of third parties. For the SQE1 assessments, you will need to understand the general rule that no duty of care is owed for omissions or to prevent third-party harm, and importantly, the exceptions to this rule. This understanding will enable you to identify scenarios where a duty might arise and apply the relevant legal principles to SQE1-style single best answer MCQs.

You should be able to distinguish non-feasance (pure omissions) from misfeasance (positive acts that make things worse), identify when a defendant’s positive conduct has created or increased a risk, and evaluate whether a special relationship (with the claimant or with the third party wrongdoer) brings the case within a recognised exception. Be ready to assess proximity, foreseeability, and whether imposing a duty would be fair, just and reasonable, including in cases involving public authorities and emergency services. Finally, you should recognise how foreseeability and intervening acts interact with duty analysis in third-party harm scenarios.

SQE1 Syllabus

For SQE1, you are required to understand liability in negligence for failing to act and for harm caused by third parties, with a focus on the following syllabus points:

• the general rule that there is no duty of care for pure omissions or to prevent harm caused by third parties
• the specific exceptions where such a duty may arise, including special relationships, assumption of responsibility, control over third parties, and creation of a danger
• identifying the key factors the courts consider when determining if an exception applies
• applying these principles to advise on liability in practical scenarios.
• distinguishing non-feasance and misfeasance and appreciating the limited “duty not to make things worse” where a defendant decides to intervene
• recognising the particular approach applied to public authorities (including police, fire and ambulance services): no general immunity, but duties arise only in defined circumstances, often where there is a positive act or an assumption of responsibility
• appreciating the role of foreseeability and novus actus interveniens when a third party’s conduct contributes to the damage

Test Your Knowledge

Attempt these questions before reading this article. If you find some difficult or cannot remember the answers, remember to look more closely at that area during your revision.

1. Generally, the law of negligence imposes:
   1. A duty to rescue anyone in danger.
   2. No liability for failing to act (pure omissions).
   3. A duty to prevent third parties from causing any harm.
   4. Liability for all foreseeable harm caused by inaction.
2. In which of the following scenarios might a duty of care to prevent harm by a third party arise?
   1. Witnessing a stranger being attacked in the street.
   2. A prison service supervising offenders known to be dangerous.
   3. Hearing about a potential crime from a news report.
   4. Simply owning property adjacent to where a third party causes harm.
3. The case of Home Office v Dorset Yacht Co Ltd [1970] AC 1004 primarily established an exception to the general rule based on:
   1. Assumption of responsibility by the defendant for the claimant.
   2. A special relationship between the claimant and the third party.
   3. The defendant having control over the third party who caused the harm.
   4. The defendant creating a source of danger negligently.
4. A 'special relationship' sufficient to create a duty to act positively might exist between:
   1. Two strangers meeting briefly on a train.
   2. A shopkeeper and a customer browsing items.
   3. An employer and their employee concerning workplace safety.
   4. Two drivers involved in a minor collision with no injuries.

Introduction

In the law of negligence, a fundamental principle is that liability typically arises from positive acts rather than failures to act. This means there is generally no legal duty imposed on individuals to intervene to prevent harm or to rescue others from danger, often referred to as the 'no duty for omissions' rule. Similarly, the law does not usually require a person to prevent a third party from causing harm to another. These rules are rooted in the concept of individual autonomy and the reluctance of the law to compel positive action. However, these general principles are subject to important exceptions, where the specific circumstances or relationship between the parties justify imposing a duty of care. Understanding these exceptions is essential for determining liability in negligence.

The policy reasons for limiting duties in omissions cases include avoiding indeterminate liability, respecting personal freedom to choose whether to act, and recognising practical constraints (who should act, when, and to what extent). The courts are therefore cautious about imposing duties to protect against third-party harm unless the defendant’s position or conduct creates sufficient proximity and a compelling reason for responsibility.

The General Rule: No Duty for Omissions or Third-Party Acts

The starting point in negligence is that the common law does not impose liability for pure omissions. A failure to act, even where such action could prevent harm, does not typically give rise to a duty of care. This principle was affirmed in cases like Smith v Littlewoods Organisation Ltd [1987] AC 241, where it was emphasised that the law is hesitant to compel individuals to act for the benefit of others, distinguishing between making things worse (misfeasance) and failing to make things better (non-feasance).

Key Term: Omission
A failure to act. In negligence, liability is generally not imposed for a 'pure' omission where the defendant has not created the risk of harm.

Key Term: Misfeasance and Non-Feasance
Misfeasance refers to positive acts which worsen the situation; non-feasance refers to a pure omission. The common law is more willing to impose duties in misfeasance cases than in non-feasance cases.

Similarly, there is no general duty to prevent a third party from causing damage. A defendant is not usually liable for harm inflicted upon the claimant by someone else, even if the defendant could have foreseen and prevented that harm.

Key Term: Third Party
A person separate from the claimant (the person suffering harm) and the defendant (the person whose liability is in question).

The rationale behind these rules includes protecting individual liberty, avoiding the imposition of indeterminate liability on potentially large groups of people, and the difficulty in defining who should be under a duty to act in any given situation.

The courts have also clarified that deciding to intervene does not, by itself, create a duty in relation to omissions. In East Suffolk Rivers Catchment Board v Kent [1941] AC 74, the Board had a power (but no duty) to repair a seawall. Having chosen to act, it was not liable in negligence merely for failing to do the job efficiently. A duty arose only if its positive acts made the situation worse. This helps frame the limits on duties: choosing to help does not automatically convert a non-feasance situation into liability unless the intervention itself increases the danger.

Public authorities generally do not owe a duty to prevent harm by third parties absent an applicable exception, but they have no blanket immunity. The Supreme Court in Robinson v Chief Constable of West Yorkshire Police [2018] clarified that ordinary negligence principles apply: a duty is more likely where the authority’s positive acts cause harm, or where it has assumed responsibility. This dovetails with the general rule against liability for pure omissions, while recognising that duties can arise in defined circumstances.

Exceptions to the General Rule

Despite the general reluctance to impose liability for omissions or the acts of third parties, courts have recognised exceptions where the relationship between the parties or the specific circumstances create a compelling reason to impose a duty. These exceptions often overlap but can be broadly categorised.

Special Relationship between Defendant and Claimant

A duty to act positively may arise where there is a special relationship between the defendant and the claimant. This relationship often involves an element of dependency, reliance, or an assumption of responsibility by the defendant for the claimant's welfare.

Key Term: Special Relationship
A pre-existing relationship between the claimant and defendant (eg, employer/employee, parent/child, doctor/patient) that justifies imposing a positive duty to act for the claimant's safety or well-being.

Examples include the duty owed by an employer to an employee to provide a safe working environment, or a parent to their child. Another basis for this exception is where the defendant has voluntarily assumed responsibility for the claimant's safety. If assumption of responsibility is established, proximity is often satisfied and it will commonly be fair, just and reasonable to impose a duty.

Key Term: Assumption of Responsibility
Where the defendant, through words or conduct, takes on a responsibility for the claimant's safety or well-being, leading the claimant to rely on that assumption.

Assumption of responsibility can arise formally (eg, a contractual duty to care for someone’s safety) or informally (eg, taking charge of a vulnerable person in a dangerous situation). A clear assumption followed by reliance is important; mere presence or bystander status is generally insufficient.

In the employment context, this overlaps with the employer’s non-delegable duty to take reasonable care of employees (safe staff, systems, plant and premises). Where an employer knows or ought to know of particular risks to an employee and can reasonably take steps to mitigate them, failing to do so may amount to a breach of a positive duty rather than a pure omission.

Worked Example 1.1

Ahmed agrees to supervise a school trip. During the trip, one of the children, Chloe, wanders off near a busy road while Ahmed is distracted. Chloe is subsequently injured by a car. Does Ahmed owe Chloe a duty of care regarding his failure to supervise?

Answer:
Yes, Ahmed likely owes Chloe a duty of care. By agreeing to supervise the trip, Ahmed assumed responsibility for the safety of the children, including Chloe. This creates a special relationship imposing a positive duty to take reasonable care for their safety, which includes adequate supervision to prevent foreseeable harm like wandering near traffic. His failure to supervise could constitute a breach of this duty.

A similar principle operates where a defendant takes control of a person who is intoxicated or otherwise vulnerable. Once the defendant undertakes care in circumstances where the claimant is at risk, failing to take reasonable steps may result in liability, not for the omission per se, but because the defendant’s assumption of responsibility created proximity and justified a positive duty.

Special Relationship between Defendant and Third Party

A duty to control a third party may arise if the defendant has a special relationship with that third party, characterised by control or supervision.

Key Term: Control
The practical ability and authority to influence or direct the actions of another person or the management of a situation.

This exception is exemplified by Home Office v Dorset Yacht Co Ltd [1970] AC 1004, where the Home Office was held liable for damage caused by young offenders who escaped from custody due to the negligence of prison officers. The officers had control over the offenders, and it was foreseeable that they might cause damage if they escaped.

Control-based duties also arise in settings such as schools, nurseries, and psychiatric facilities. If those under the defendant’s control are known (or ought reasonably to be known) to pose a risk of harm to others, the defendant may owe a duty to take reasonable steps to prevent that harm. This does not impose an obligation to achieve perfect safety, but it does require reasonable measures commensurate with the risk and the degree of control exercised.

Worked Example 1.2

A psychiatric hospital detains patients known to have violent tendencies. Due to negligent security procedures, a patient escapes and assaults a member of the public nearby. Does the hospital potentially owe a duty of care to the member of the public?

Answer:
Yes, the hospital may owe a duty of care. The hospital has control over its detained patients, particularly those known to be dangerous. This control creates a special relationship between the hospital (defendant) and the patient (third party), giving rise to a duty to take reasonable steps to prevent the patient from causing foreseeable harm to others, such as members of the public, if they escape.

Similar reasoning was applied in Carmarthenshire County Council v Lewis [1955] AC 549, where a school’s inadequate supervision allowed a young child to wander onto a road, causing a driver to swerve and suffer fatal injuries. Because the school exercised control and had a duty to prevent pupils from becoming a danger to others, liability was imposed.

Creation of a Source of Danger

Where a defendant creates a source of danger through their own actions, they may owe a duty to take reasonable steps to prevent a third party from interfering with that danger and causing harm to the claimant.

Key Term: Creation of Danger
The situation where a defendant’s positive act creates or increases a risk of harm. A duty may arise to take reasonable steps to guard against foreseeable third-party interference with that danger.

If the defendant’s conduct makes it more likely that third parties will cause harm (eg, by leaving hazardous equipment accessible), the duty analysis moves away from pure omission. The focus is on whether the defendant’s positive act created a foreseeable risk that third parties would exploit or interact with the danger, leading to harm.

Foreseeability is important. In Topp v London Country Bus Ltd [1993] 1 WLR 976, a bus company left a bus in a lay-by with the keys in the ignition. The bus was stolen and later involved in a fatal collision. The Court of Appeal held that the theft and subsequent negligent driving were not sufficiently foreseeable in the circumstances to impose a duty on the bus company. By contrast, if the defendant knows of repeated interference by third parties or of particular vulnerabilities (eg, a location plagued by theft), foreseeability may be established and a duty to take reasonable protective steps can arise.

Worked Example 1.3

A contractor leaves a deep, unfenced excavation pit overnight on a public pathway without adequate lighting or warnings. Some children later push another child into the pit as a prank, causing injury. Does the contractor potentially owe a duty regarding the actions of the children?

Answer:
Yes, the contractor likely owes a duty. By creating a source of danger (the unlit, unfenced pit) in a public area, the contractor made it reasonably foreseeable that a third party (like children playing) might interact with the danger, leading to harm. The contractor had a duty to take reasonable precautions (fencing, lighting, warnings) to prevent such foreseeable harm resulting from the danger they created.

In Smith v Littlewoods, owners of a disused cinema were not liable when intruders started a fire unless they knew, or ought to have known, of the risk of third-party interference and failed to take reasonable steps. This illustrates that liability turns on the defendant’s knowledge (actual or constructive) and the foreseeability of third-party misuse of the danger created by the defendant.

Failure to Abate a Known Danger Created by a Third Party

An occupier of land may owe a duty if they know, or ought to know, that a third party has created a danger on their land, and they fail to take reasonable steps to abate (remove or reduce) that danger. This overlaps significantly with principles of occupiers' liability but can arise in negligence too.

Knowledge and reasonable steps are key. In Barker v Herbert [1911] 2 KB 633, the defendant landowner had installed protective railings which were later removed by children. The court held the owner was not liable because he had recently inspected the railings and had no reason to suspect they had been removed; the stranger’s act was not foreseeable in the circumstances. Where, however, the occupier is aware (or should be aware) of repeated interference, failing to secure or warn may amount to a breach of duty.

Worked Example 1.4

The owner of a derelict building knows local youths regularly enter and set small fires inside. The owner takes no steps to secure the site despite repeated incidents known to him. A more serious fire later spreads to neighbouring properties causing damage. Is the owner potentially liable?

Answer:
Yes. Because the owner knew (or ought to have known) of repeated third-party interference and the escalating risk, a duty to take reasonable steps to abate the danger (eg, secure the site, install deterrents, notify authorities) arises. Failing to act in those circumstances can amount to negligence even though the immediate cause was third-party misconduct.

Emergency Services and Public Authorities: Assumption of Responsibility and Positive Acts

Public bodies are subject to ordinary negligence principles, but duties to prevent third-party harm are tightly controlled. Two recurring patterns are:

• A duty may arise where a public authority has assumed responsibility to an individual who reasonably relies on it. For example, once an ambulance service accepts a 999 call and provides assurances, failing to attend without reasonable justification may be actionable because reliance creates proximity.

• Liability is more likely where the authority’s positive acts cause harm or make the situation worse. By contrast, failing to confer a benefit (pure omission) usually does not attract liability.

Turning off a functioning sprinkler system during a fire is a positive act that increases danger. In such a case, the fire service may be liable because it made the situation worse. Conversely, failing to attend promptly may be treated as an omission unless there is an assumption of responsibility to the particular claimant.

Worked Example 1.5

The fire service attends a warehouse fire. A senior officer orders the working sprinkler system to be turned off, believing it is ineffective. The fire spreads and damage worsens. Could the fire service owe a duty?

Answer:
Yes. This is misfeasance, not non-feasance. By turning off a functioning sprinkler system during a fire, the fire service made the situation worse. A duty and breach may be found because the harm flowed from a positive act which increased the risk of damage.

Worked Example 1.6

An ambulance service accepts a 999 call for a patient in respiratory distress and indicates an ambulance is en route. Without good reason, the ambulance is not dispatched and the patient suffers avoidable harm. Could a duty arise?

Answer:
Yes. Acceptance of the call and indication of attendance can amount to an assumption of responsibility to the individual, creating proximity. Failing to attend without justification in reliance circumstances may lead to liability.

These examples show the careful line courts draw in public body cases: a duty is far more likely where the authority’s conduct involves positive acts causing harm or a clear assumption of responsibility to an identified individual.

Police and Crime Prevention: No General Duty

There is no general duty on the police to protect individuals from harm by third parties or to prevent crime. However, ordinary negligence principles apply to police activities. Where police officers carry out a positive act that causes foreseeable harm (eg, an unsafe arrest manoeuvre in a crowded street), a duty can arise. Equally, if officers assume responsibility towards a specific individual, that may create proximity. Absent assumption of responsibility or positive harm-causing conduct, failing to prevent criminal acts will generally be treated as non-feasance and fall within the general rule.

Worked Example 1.7

A local authority housing department knows a tenant has threatened violence towards a neighbour after a formal warning meeting. The department does not inform the neighbour of the specific risk. The tenant later assaults the neighbour. Is the authority likely to owe a duty?

Answer:
Usually no. Without a clear assumption of responsibility to the neighbour or other special factors, the authority’s failure to warn is a pure omission. Imposing a duty to warn in such situations is generally not considered fair, just and reasonable. Different conclusions may follow if the authority undertakes to protect a specific person who reasonably relies upon it.

Worked Example 1.8

A bus company leaves a bus unattended overnight with the keys in the ignition at a location with a known pattern of vehicle thefts. The bus is stolen and, while negligently driven, injures a pedestrian. Is the bus company potentially liable?

Answer:
It depends on foreseeability and context. If the circumstances (eg, known patterns of theft and accessibility) made theft and negligent driving a foreseeable consequence of leaving the keys, a duty to take reasonable preventative steps (eg, remove keys, secure the vehicle) may arise. If the theft and subsequent harm were not reasonably foreseeable, no duty will be imposed.

Exam Warning

Be careful to distinguish liability for omissions/third-party acts in general negligence from the specific statutory duties owed by occupiers under the Occupiers' Liability Acts 1957 and 1984. While an occupier might be liable under the Acts for dangers created by third parties on their premises, a non-occupier's liability would depend on establishing one of the negligence exceptions discussed here (e.g., creation of danger, control).

Revision Tip

When analysing a problem question involving harm caused by a third party, first identify if the defendant created the initial risk or had control over the third party or the claimant. If not, the general rule of no liability likely applies, unless there's a clear assumption of responsibility.

Causation and Intervening Acts: How Third-Party Conduct Fits In

Duty analysis often sits alongside questions of causation. Even where a duty exists, a third party’s independent act may sometimes break the chain of causation (novus actus interveniens). The courts consider whether the intervening act was reasonably foreseeable and whether it fairly falls within the scope of the defendant’s duty.

• If a defendant’s creation of danger makes third-party interference foreseeable, the chain is less likely to be broken (eg, foreseeable vandalism at unsecured premises).
• If the third-party act is unusual, unexpected, or outside the scope of the risk created, the chain may be broken (eg, a highly unusual criminal act not reasonably foreseeable given the circumstances).

This reflects the overall approach to responsibility: duty is more readily found where the defendant’s position or conduct created or increased the risk, and causation is more readily found where the harm is the kind of risk which the duty aimed to prevent.

Key Point Checklist

This article has covered the following key knowledge points:

• The general rule in negligence is that there is no duty of care imposed for pure omissions (failure to act).
• Similarly, there is generally no duty to prevent harm caused by the actions of a third party.
• Exceptions to the general rule exist where there is a sufficient proximity or relationship justifying a positive duty.
• A duty may arise from a special relationship between the defendant and the claimant (often involving an assumption of responsibility).
• A duty may arise from a special relationship between the defendant and the third party who causes the harm (usually involving control).
• A duty may arise where the defendant has negligently created a source of danger which is interfered with by a third party.
• A duty may arise where an occupier fails to abate a known danger created by a third party on their land.
• In public authority cases, duties are more likely where there is a positive act causing harm or an assumption of responsibility; failing to confer a benefit is usually treated as a pure omission.
• Foreseeability is central: liability is more likely where third-party interference with a danger created by the defendant is foreseeable; lack of foreseeability often defeats duty and/or causation.
• Causation and intervening acts interact with duty analysis—novus actus interveniens may break the chain where third-party acts are outside the scope of foreseeable risk.

Key Terms and Concepts

• Omission
• Third Party
• Special Relationship
• Assumption of Responsibility
• Control
• Creation of Danger
• Misfeasance and Non-Feasance