Legal Definitions - intervening act

An intervening act refers to an event or action that occurs *after* an initial wrongful act or negligence, but *before* the final injury or damage takes place. This subsequent act or event contributes to the ultimate harm. The legal significance of an intervening act lies in whether it is so independent and unforeseeable that it breaks the chain of causation between the original wrongful act and the resulting harm, potentially relieving the initial wrongdoer of liability.

• Example 1: Construction Site Negligence and Vandalism

  A construction company negligently leaves a large trench uncovered and unmarked overnight, violating safety regulations. Later that night, a group of teenagers, completely unrelated to the construction company, trespasses onto the site and, while playing near the trench, one of them falls in and is seriously injured.

  Explanation: The construction company's negligence in leaving the trench uncovered is the initial wrongful act. The teenagers' trespassing and playing near the trench is the intervening act. A court would need to determine if the teenagers' actions were a foreseeable consequence of leaving the trench unsecured, or if their actions were so independent and unforeseeable that they broke the chain of causation, thereby affecting the construction company's liability for the injury.

• Example 2: Defective Product and User Modification

  A company manufactures a kitchen appliance with a known design flaw that makes it prone to overheating. A consumer purchases the appliance, but before using it, they intentionally remove a critical safety sensor, believing it will improve performance. The appliance then overheats and causes a fire, damaging the consumer's kitchen.

  Explanation: The manufacturer's production of a defective appliance is the initial wrongful act. The consumer's deliberate removal of the safety sensor is an intervening act. The legal question would be whether the consumer's modification was an unforeseeable act that broke the causal link between the manufacturer's defect and the fire, potentially reducing or eliminating the manufacturer's liability.

• Example 3: Medical Malpractice and Subsequent Negligence

  A surgeon negligently performs an operation, leaving a surgical instrument inside a patient. The patient experiences severe pain and is rushed to another hospital. At the second hospital, a different doctor, also acting negligently, misdiagnoses the cause of the pain and delays treatment, leading to a more severe infection and permanent damage to the patient.

  Explanation: The first surgeon's negligence (leaving the instrument) is the initial wrongful act. The second doctor's negligent misdiagnosis and delayed treatment constitute an intervening act. A court would assess whether the second doctor's negligence was an independent and unforeseeable event that exacerbated the patient's condition, potentially limiting the first surgeon's liability for the full extent of the patient's ultimate harm.