The U.S. Air Force said two Americans were killed and 40 injured in the weekend air show catastrophe at Ramstein Air Base in West Germany. It said seven of the Americans still were hospitalized in Germany and seven had been evacuated to the Brooke Medical Center in San Antonio. An Air Force announcement said the 52 dead included two Americans, the three Italian aerobatic pilots whose collision caused the catastrophe, 17 Germans, 21 unidentified people, and nine others who died at local hospitals whose nationalities have not been reported.