Thirty years ago today, a United Airlines plane crashed-landed in Sioux City and killed 112 people; 184 survived. Flight 232 was headed from Denver to Chicago on July 19th, 1989 when it had a hydraulic failure. The DC-10 plane's No. 2 engine's fandisk broke apart, severing all three hydraulic line systems on the aircraft. Captain Al Haynes radioed in to an air traffic controller.