Legal Definitions - intervening agency

An intervening agency refers to a new, independent event or action that occurs after an initial wrongful act and significantly contributes to the resulting harm. This new event is considered so separate and powerful that it breaks the direct causal link between the original act and the final injury. When an intervening agency is present, it can relieve the person who committed the initial wrongful act from legal responsibility for the ultimate harm, because the intervening agency is seen as the true, independent cause of that harm. For an event to be considered an intervening agency, it must generally have been unforeseeable by the person who committed the initial act.

• Example 1: Medical Malpractice Following an Accident

  Imagine a driver, Mr. Smith, negligently runs a red light and collides with Ms. Jones's car, causing her to suffer a broken arm. During the surgery to repair Ms. Jones's arm, the surgeon, Dr. Lee, makes a severe and unforeseeable error, resulting in permanent nerve damage to Ms. Jones's hand, which was not an expected complication of the original injury. While Mr. Smith is responsible for Ms. Jones's broken arm, Dr. Lee's egregious surgical error could be considered an intervening agency. This means Dr. Lee's independent and unforeseeable negligence broke the chain of causation between Mr. Smith's initial act and the permanent nerve damage, potentially limiting Mr. Smith's liability for that specific, more severe injury.

• Example 2: Construction Site Vandalism

  A construction company leaves a deep trench uncovered and inadequately marked overnight, which is a negligent safety violation. However, before anyone can fall in, a group of vandals intentionally removes all the warning signs and safety barriers, and then pushes a heavy piece of construction equipment into the trench, causing significant damage to underground utility lines. The vandals' deliberate and unforeseeable actions of removing the warnings and causing damage to the utilities would likely be considered an intervening agency. While the construction company was negligent in leaving the trench exposed, the vandals' independent acts are the direct cause of the utility damage, potentially relieving the construction company of liability for that specific harm.

• Example 3: Defective Product and Intentional Misuse

  A manufacturer produces a kitchen appliance with a minor electrical flaw that, under very specific and unlikely circumstances, could cause a small spark. However, a user, Mr. Davis, intentionally modifies the appliance against all safety warnings, bypassing several safety mechanisms, and uses it in an extremely dangerous and unintended manner to perform an unrelated task. This extreme misuse causes the appliance to overheat, explode, and severely injure Mr. Davis. The manufacturer's initial minor flaw is a cause, but Mr. Davis's deliberate, extreme, and unforeseeable modification and misuse of the product would be considered an intervening agency. His actions broke the causal link between the minor defect and the severe explosion, potentially relieving the manufacturer of liability for the explosion and severe injuries.