Two police helicopters collided over a helipad Saturday, leaving six Pasadena officers with minor injuries, officials said. A chopper that was landing came into contact with one that was taking off, Lt. Phlunte Riddle said. The collision caused the rotor blade of one of the helicopters to fall off and its tail to break, but Riddle said she didn't have further details. The injured were taken to hospitals for further evaluation after the 4 p.m. collision in Altadena. Riddle said they included a pilot and an observer in each of the Bell OH-58A helicopters and two officers on the ground. 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 NTSB will investigate.