Final answer:
A defendant is liable for a third party's actions causing deaths if they had prior knowledge of a risk or defect and failed to act responsibly. As seen with a car manufacturer knowing about brake defects, liability is assigned due to negligence. The principles behind such liability are negligence, knowledge, and causation.
Step-by-step explanation:
The defendant can be held liable for deaths caused by a third party if there was prior knowledge of a defect or risk that could lead to injury or death. An example of this is when a manufacturer continues to produce and sell an automobile despite being aware that it has a faulty brake system. If the defective brakes result in accidents, injuries, and deaths, the manufacturer liability is clear due to the negligent decision to sell a product known to be unsafe. In legal terms, this situation demonstrates a breach of duty of care and the disregard for consumer safety can lead to the manufacturer being held responsible for the consequences.
Furthermore, discussions around liability broaden to consider various sectors, such as whether health-care workers should be considered liable for following flawed procedures, or what role the government plays in regulating medical equipment and practices. In any scenario, the key aspects that establish liability include negligence, foreknowledge of risk, and the causation link between the defendant's actions and the subsequent harm.