Two television news helicopters collided Friday and crashed while covering a police pursuit in Arizona, killing at least two people. Both helicopters went down in a park in central Phoenix and caught fire. The collision happened as the two choppers broadcast live coverage of police pursuing a truck. Cameras aboard both aircraft were pointed at the ground, so viewers did not witness the accident. The first indication of trouble came when pictures from the helicopters went dead. Television station KNXV reported that it owned one of the choppers. The other was from KTVT, which reported that both the pilot and photographer were killed in the crash. Just before the collision, the driver of the truck that was being pursued had jumped out of pickup and carjacked another truck.