American Airlines and others sued in connection with the 9/11 attacks can claim the act of war defense to strict liability under a hazardous substance cleanup law, a federal judge ruled Thursday. Southern District Judge Alvin Hellerstein said in In re September 11 Litigation, 08 Civ. 9146, that the exception to the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA) was another reason owners of a building a block from the World Trade Center cannot recover for damages and cleanup.