In 1955 a man’s wife gave him a power tool for Christmas. Later a piece of wood flew out of the machine and struck him on the forehead. In 1963 the California Supreme Court ruled: “A manufacturer is strictly liable in tort when an article he places on the market, knowing that it is to be used without inspection for defects, proves to have a defect that causes injury to a human being.”
A similar rule appeared in 1965 in section 402A of the Restatement (Second) of Torts, a summary of American law. It applies even when “the seller has exercised all possible care in the preparation and sale of his product.” An injured user does not need to prove that the maker was careless. The user must show only that a defect in the product caused the injury.
The California court explained that the costs of such injuries should fall on manufacturers, not on “the injured persons who are powerless to protect themselves.” Some states have since dropped strict liability for product cases.