Legal Definitions - superseding cause

A superseding cause is an unexpected and independent event that occurs *after* someone's initial negligent action, and is so powerful that it completely breaks the connection between that initial action and a subsequent injury. When a superseding cause is present, the law considers it the true cause of the injury, thereby relieving the person who committed the initial negligent act from responsibility for that specific harm.

Here are some examples to illustrate this concept:

• Example 1: Negligent Parking and Intentional Harm

  A delivery driver negligently parks their large truck in a no-parking zone, completely blocking a crosswalk. A pedestrian, unable to use the crosswalk, steps into the street to go around the truck. While the pedestrian is in the street, an unrelated, intoxicated driver intentionally swerves onto the sidewalk and then into the street, striking the pedestrian and causing severe injuries.

  How it illustrates the term: The delivery driver's negligence created a hazard that forced the pedestrian into the street. However, the *intentional* and *reckless* act of the intoxicated driver is an unforeseeable and independent event that completely breaks the chain of causation from the delivery driver's initial negligence. The intoxicated driver's actions become the superseding cause of the pedestrian's severe injuries, potentially relieving the delivery driver of liability for those specific injuries.

• Example 2: Unsecured Construction Site and Vandalism

  A construction company leaves a deep trench uncovered and poorly lit overnight, violating safety regulations. A passerby falls into the trench, sustaining a broken leg. Before emergency services can arrive, a group of vandals intentionally pushes a heavy concrete barrier into the trench, causing *further, severe* injuries to the already injured passerby, including internal bleeding.

  How it illustrates the term: The construction company's negligence caused the initial broken leg. However, the deliberate and malicious act of the vandals pushing the barrier into the trench is an independent and unforeseeable criminal act. This act becomes a superseding cause for the *additional, severe* injuries, potentially relieving the construction company from liability for those specific injuries caused by the vandals, as the vandals' actions broke the causal link.

• Example 3: Defective Product and Extreme Misuse

  A manufacturer produces a children's toy with a small, detachable part that could pose a choking hazard if swallowed. A parent, fully aware of this choking hazard, intentionally grinds down the toy into a fine powder and mixes it into their child's food, causing a severe allergic reaction and hospitalization (unrelated to choking).

  How it illustrates the term: While the toy had a design flaw (choking hazard), the parent's deliberate and extreme act of altering the toy and feeding it to the child in a completely unforeseen manner is a superseding cause. This intentional misuse breaks the chain of causation from the manufacturer's original defect to the child's allergic reaction, potentially absolving the manufacturer of liability for the allergic reaction.