Superseding Cause

The term superseding cause refers to some event that occurs after the initial act that caused an accident, or some other injury. A superseding cause, also known as an “intervening cause,” may be proven to have substantially caused the accident. This has an effect on who should be held liable for the damages caused by the accident. To explore this concept, consider the following superseding cause definition.

Definition of Superseding Cause


  1. An unforeseeable event that interrupts the chain of causation, becoming the actual cause of the accident.

Origin of Supersede

1485-1405       Latin    supersedēre  (to sit above or upon)

What is Superseding Cause

In a civil lawsuit in which a defendant has done something negligent that caused the plaintiff’s damages, it is possible for the defendant to avoid liability. This might be done by proving there was some other event that happened after his act that led to the accident, or to the plaintiff’s damages, at least in substantial part.

To break this down, consider that very few occurrences happen in a vacuum. One person makes a mistake, causing something bad to happen, then other things simply go wrong – sometimes by a different person’s mistake. It is the court’s job, once someone sues, to determine just who is responsible for the plaintiff’s damages, even if the responsibility must be divided.

For example:

Quinn is in an automobile accident, which was caused by Brenda’s running a stop sign. Quinn’s car is damaged in the front quarter panel. Quinn just has time to realize his arm hurts before a tow truck, happening on the scene, rams into Quinn’s car, pushing it into a ditch. Quinn’s car ended up totaled, and he suffered a broken arm, two broken ribs, and a severe neck strain.

Quinn files a civil lawsuit against Brenda because she ran the stop sign and hit him. Quinn seeks payment for his totaled car, as well as for his medical bills, and pain and suffering, to the tune of more than $10,000. At trial, Brenda claims she cannot be held solely responsible, as the tow truck hitting Quinn’s car caused a great deal of the damages, and his injuries.

In this example, the superseding cause was the tow truck running into the already damaged vehicle. While Quinn’s damages and injuries could be foreseen as the result of Brenda running the stop sign, the impact of a tow truck that happened by could not.

Proximate Cause, Superseding Cause, and Intervening Cause

There are three ways to categorize cause in any situation in which someone experiences a loss due to someone else’s actions.

Proximate Cause

Proximate cause refers to the act that most directly resulted in someone’s damages or injury. This need not be the cause closest in time to the incident, nor even the first event to set off a sequence of events leading to the injury. Proximate cause produces a consequences that is foreseeable, or even expected. For instance, a house fire is a foreseeable consequence of allowing a young child to play with matches.

In order to determine whether someone’s actions were the proximate cause of another’s damages, the courts apply what is know as the “but for” test. In doing this, it must be considered whether the damages or injury would not have happened but for the defendant’s negligent or reckless actions. While the answer to this test establishes proximate cause, it does not necessarily establish who is liable for the plaintiff’s damages, as other factors could have come into play.

Intervening Cause

An intervening cause is a separate act of yet another party, which interrupts the direct connection between the defendant’s negligent or reckless act, and the damages or injury suffered by the plaintiff. While the person who committed the act considered to be the proximate cause of a plaintiff’s damages is held liable, he may escape being held liable if he can show that some subsequent event – the intervening cause – was actually the cause of the damages or injury.

What sets an intervening cause apart from a superseding cause (discussed below) is that it is a foreseeable outcome of the person’s actions.

For example:

Manny agrees to keep Ron’s horse in his corral for a week while Ron moves. Manny puts the horse in a pen has a section of fence that is damaged, and falling apart. During a thunder storm, the horse is spooked, and runs through the damaged section, breaking his leg so severely that he has to be put down. In this situation, a horse kept in a damaged corral is quite likely to escape, or to be injured.

Manny might attempt to escape liability – and the hefty price tag for the horse – by claiming that the storm was an intervening cause that resulted in the horse’s injuries. However, the outcome of Manny’s actions in putting the horse in the damaged pen could reasonably lead to the injuries. In this case, Manny cannot escape liability, even though there was an intervening cause.

Superseding Cause

A superseding cause is very similar to an intervening cause, in that it refers to a subsequent event that causes, or adds to the severity of, the damages. It is different, however, in that the subsequent event is something that could not be foreseen as a consequence. As an example of a superseding cause, consider this alternative sequence of events:

Manny puts Ron’s horse into his damaged corral, then retires for the evening. During the night a storm arises, and hurricane-force winds pick up an empty refrigerator in the neighbor’s yard, and hurls it at the horse, striking him, and forcing him into the damaged section of the fence. The horse is severely injured.

The high winds and abandoned refrigerator in this example are a superseding cause – something that simply could not have been foreseen, and which occurred after Manny put the horse into a damaged pen. In this example, superseding cause may enable Manny to escape liability for the horse’s demise.

Superseding Cause Example in Negligent Homicide

In March 2000, Teresa Butts was driving down a dark and rainy night, when she struck a homeless man crossing the street. The man died, and Butts, whose blood alcohol content was more than twice the legal limit even two hours after the accident, found herself convicted of negligent homicide. She appealed the conviction on a number of grounds, one of which was failure of the judge to instruct the jury properly regarding superseding and intervening cause.

Butts claimed that the streetlight wasn’t working where the accident occurred, and that the man shouldn’t have been crossing the street wearing dark clothing, and not at a crosswalk. She claimed that his own actions amounted to contributory negligence, and should be considered a superseding cause, relieving her of liability for the man’s death.

In response to these claims, the appellate court ruled that an intervening cause can only be considered a superseding cause if it was “so unforeseeable that the actor’s negligent conduct, though still a substantial causative factor, should not result in the actor’s liability.” The court held that the defendant could only be relieved of liability for the victim’s death if his own actions were the sole cause of his death.

Further, the court explained that, in order for an act to be considered a superseding cause, it must be the act of someone or something other than the original actor and the victim. Additionally, a superseding act must have occurred after the original actor’s negligent act was committed.

Not only was the victim directly injured by the defendant’s actions (no third party involved), but his act of walking across the street 90 feet from a crosswalk, and while intoxicated, occurred before, or perhaps concurrently with, the defendant’s negligent act of driving under the influence.

Example of Superseding Cause vs. Proximate Cause in House Fire

In 2007, a power outage occurred in a Maryland neighborhood, leaving residents in the dark. Children in one rental home, who slept in their basement bedrooms, had lit a candle before going to sleep. The candle foreseeably started a fire, but when the smoke detectors – which were hard-wired into the home, and had no battery backup – failed to wake the children, and there were no exits from the basement other than the main staircase, two children died, and three others were severely injured in the fire.

In the building of the home, the builder did not finish the basement, and did not include additional exits, as it was never intended to serve as bedrooms. The landlord had finished the basement, though he did so without obtaining the required permits. The family filed a civil lawsuit, naming a host of defendants, including the landlord, the manufacturer of the smoke alarms, the home builder, the electrician, and the city inspector.

Both the smoke alarm manufacturer and the building contractor filed motions to dismiss, claiming that there were many events that occurred between their supposed negligence and the incident that caused the children’s deaths and injuries. The companies claimed that all of these events amounted to superseding causes that should absolve them of liability. While the circuit court granted the dismissals, the plaintiffs appealed.

The appellate court found that a proximate cause relies on whether the original actor should have been able to foresee the danger or harm. An intervening cause, such as the failure of a home builder to include sufficient exits from a home, may rise to the level of a superseding cause if it is so extraordinary or unusual that its interference, or consequences thereof, could not have been foreseen or anticipated.

The appellate court was tasked with determining whether any of the intervening causes rose to the level of superseding cause, thus absolving the defendants of liability, supporting their dismissals from the lawsuit. Ultimately the court ruled that reasonable minds could very surely come to different conclusions about that issue, and therefore it is a question of fact that should be determined by a jury. The court of appeals denied the motions to dismiss the home builder and smoke alarm manufacturer.

 Related Legal Terms and Issues

  • Civil Lawsuit – A lawsuit brought about in court when one person claims to have suffered a loss due to the actions of another person.
  • Contract – An agreement between two or more parties in which a promise is made to do or provide something in return for a valuable benefit.
  • Damages – A monetary award in compensation for a financial loss, loss of or damage to personal or real property, or an injury.
  • Defendant – A party against whom a lawsuit has been filed in civil court, or who has been accused of, or charged with, a crime or offense.
  • Liability – Responsibility for payment of damages, or for other court-imposed penalties in a civil lawsuit.
  • Negligence – Failure to exercise a degree of care that would be taken by another reasonable person in the same circumstances.
  • Plaintiff – A person who brings a legal action against another person or entity, such as in a civil lawsuit, or criminal proceedings.