Background
A homebuilt Dragon Fly aircraft experienced a ground loop. Following this event, other aircraft in the VFR traffic pattern were instructed to go around. These included a Cessna 152 (registration N93604) flown by a student pilot. After the Dragon Fly was cleared from the runway, a Cessna 172 (registration N48003) entered the pattern, bringing the total to six aircraft in the pattern and one pilot waiting to depart. The Cessna 172 had entered the pattern ahead of the Cessna 152.
Sequence of Events
The tower controller informed the student pilot in the Cessna 152 that he was number three in the pattern, "following a Cessna on base." The student acknowledged. Shortly thereafter, the number one aircraft landed, and the pilot waiting to depart was cleared for takeoff. As the Cessna 172 and Cessna 152 continued in the pattern, the controller asked the student if he was still following the Cessna ahead. The student replied, "That's affirmative."
Collision
On final approach, the two aircraft converged and collided, then fell to the ground. The controller, who was busy, did not see the accident.
Aftermath
The pilot-in-command of the Cessna 172 was fatally injured. The second pilot (copilot) in the Cessna 172 and the pilot of the Cessna 152 were seriously injured.
Probable Cause
Not stated in the source.