Two police helicopters collided over a helipad Saturday, leaving five police officers and a civilian with minor injuries, officials said. Police believed the collision occurred when the rotator blades of a chopper that was landing and one that was taking off touched, dpa quoted Lt. Phlunte Riddle as saying. The collision caused the blade of one of the helicopters to fall off and its tail to break. The injured were taken to hospitals for further evaluation after the 4 p.m. collision in Altadena. Riddle said they included five police officers and a civilian observer in one of the two Bell OH-58A helicopters. One helicopter crew was on routine patrol and the other was assigned to monitor traffic from the UCLA-Southern California football game at the Rose Bowl, she said. The weather was drizzly and cloudy at the time of the accident. FAA spokesman Allen Kenitzer said his agency and the National Transportation Safety Board will investigate.