Proximate Cause and Foreseeability: The Causation Test in Negligence

To recover compensation in a personal injury claim, you must prove proximate causation and foreseeability. Causation requires showing the injury was a natural, predictable consequence of the defendant’s negligent conduct. The defendant may try to avoid legal liability by claiming intervening or superseding causes broke the chain of legal causation.

For legal advice about proving proximate cause and foreseeability in an injury claim, talk to your personal injury attorney.

Proving Causation in a Personal Injury Lawsuit

In a personal injury lawsuit, the injury victim must prove the defendant caused the accident and is liable for damages. Most personal injury claims in tort law are based on negligence. The elements of a negligence claim include:

• The defendant owed a duty of care to the plaintiff
• The defendant breached their duty by failing to act as a reasonable person
• The defendant’s actions (or inactions) caused the plaintiff’s injuries
• The plaintiff suffered actual harm as a result

Causation is an essential element of proving negligence in a personal injury case. To recover compensation for a car accident, slip-and-fall, or medical malpractice case, you need to prove the defendant’s actions caused your injuries. The causation test for a negligence claim includes both the factual cause and the legal cause.

Actual Cause in Fact

The injury victim must prove the defendant was the actual cause in fact. The but-for test means that but for the defendant’s action, the accident would not have happened. For example, if the driver had not run the stop sign, they would not have hit the cyclist crossing the intersection.

The but-for test can seem simple, but it gets more complicated when multiple causes contribute to an accident. For example, a driver has a negligent mechanic repair the brakes, but the brakes fail when the driver tries to stop at an intersection and hits a cyclist riding at night without the required lighting. The cyclist then rides into an open manhole that a repair crew negligently left open.

In this scenario, multiple but-for causes could explain the bizarre accident. The but-for test does not always establish clear liability. Jurisdictions generally also require the plaintiff to show the accident was a foreseeable consequence of the defendant’s actions.

Proximate Cause and Foreseeability

The plaintiff can prove the defendant was the legal cause of the accident using the proximate cause or foreseeability test. Most jurisdictions base legal cause on whether the defendant’s conduct created a foreseeable risk of harm. A defendant is liable if the injury was a reasonably foreseeable result of their breach of duty of care.

For example, causing a car accident is a foreseeable risk of running a red light. However, running a red light can also foreseeably cause a collision that forces another car into a nearby house, injuring residents or starting a house fire.

The scope of liability under proximate causation is not always clear. In some cases, a defendant acts unreasonably where there is a foreseeable risk of harm, but the actual harm is not a foreseeable risk of the defendant’s actions.

For example, a security guard negligently leaves the door of an explosives factory unlocked. A child enters the factory and goes to the roof, where lightning strikes them. The security guard would likely be liable for injuries caused by an explosion, but a lightning strike is not a foreseeable harm.

Were There Intervening Causes To Break the Chain of Causation?

Intervening acts can break the causal chain. An intervening event occurs after the defendant’s conduct and contributes to the harm, but it relieves the defendant of liability only if it is a superseding cause. Examples include a third party’s criminal acts, freak accidents, and natural disasters.

For example, a driver runs a stop sign and hits a cyclist. The driver’s actions are the proximate cause. The cyclist is taken to the hospital, but an earthquake causes the emergency room to collapse, killing the cyclist. The earthquake is a superseding cause that the driver could not have reasonably foreseen.

Multiple Causes of an Injury Accident

Accidents can have multiple causes, with multiple parties sharing legal responsibility for causing the victim’s injuries. For example, two drivers may both run a red light, crash into each other, and injure a pedestrian legally crossing the intersection. Which driver must pay for the victim’s injury damages? If one driver is more responsible for the accident, can the other driver also recover compensation?

When multiple parties are involved in an accident, the court can determine causation using the substantial factor test. Under the substantial factor test, a defendant is liable if their conduct was a substantial factor (more than a remote or insignificant factor) in causing the plaintiff’s injuries.

For example, if your alarm clock did not go off, you left your home 30 minutes later than usual, and you were involved in a car accident on the way to work, the alarm clock is not a substantial factor in causing the accident.

When multiple causes contribute to an accident, each can be a substantial factor in causation. For example, campers in two areas of a forest let their campfires burn out of control, leading to a larger fire that caused property damage and injuries. Each fire could have spread and caused the same overall damage, so both campers are liable.

Compensation in a personal injury claim involving multiple liable parties depends on state law. Two separate issues can affect whether you recover compensation, who pays, and how much you recover. When two parties breach their duties of care and cause the victim’s injuries, the court or jury can allocate liability between them.

Comparative Fault and Contributory Negligence

Contributory negligence limits how much an injury victim can recover if they shared liability for the accident. In contributory negligence states, the victim cannot recover any compensation if they contributed to the accident.

In a modified comparative negligence state, the victim can recover compensation up to their share if their fault is below the applicable 50% or 51% threshold. In a pure comparative negligence state, the victim can recover compensation, reduced by their level of fault.

For example, a cyclist riding at night does not have the required lights and a speeding driver hits the cyclist, causing $100,000 in damages. The court finds the speeding driver 90% at fault and the cyclist 10% at fault. The cyclist’s possible recovery, depending on state law, is the following:

• Contributory negligence: $0 in compensation
• Modified comparative negligence: $90,000 in compensation
• Pure comparative negligence: $90,000 in compensation

Joint and Several Liability

If the injury victim had no part in causing the accident but there are two or more negligent parties, state law can also complicate the injury victim’s recovery options. Joint and several liability determines whether each party pays only their share of fault or the victim can recover everything from one responsible party, who must then recover the other parties’ shares from them.

States take one of three approaches. In states with pure joint and several liability, the injury victim can recover the full amount from any party, even if that party was a minor cause of the accident. In states with modified joint and several liability, the injury victim can recover the full compensation from any party that is 50% or 51% at fault. In states with pure several liability, the victim can recover only compensation equal to the defendant’s level of fault.

Do You Always Need To Prove Causation?

Yes, you always need to prove causation to hold a party liable in a negligence claim. You may not need to prove the defendant breached their duty of care in a strict product liability claim or a car accident claim based on negligence per se, but you must show causation.

In a product defect lawsuit, you don’t have to prove the manufacturer breached the standard of reasonable care, but you do need to show the defendant’s defective product caused your injuries. In a negligence per se car accident lawsuit, the defendant’s violation of traffic laws establishes their breach of the duty of care. However, you still need to prove the traffic violation caused your accident.

Contact a Personal Injury Lawyer To Prove Causation

Proving causation in a negligence lawsuit can be complex because you may need expert testimony to prove the defendant’s actions were the actual cause and your injuries were a foreseeable result. For example, proving direct cause in a medical malpractice lawsuit often requires medical expert testimony. If you have questions about proving proximate cause and foreseeability in a negligence lawsuit, contact a personal injury attorney for legal advice.