The low-wing airplane pilot’s failure to ensure that the airplane was aligned with the correct runway, which resulted in a collision with the high-wing airplane on final approach. Contributing to the accident was the controller’s failure to provide timely and adequate traffic information to either airplane and his failure to recognize the developing conflict and to act in a timely manner. Also contributing was the Federal Aviation Administration’s insufficient staffing of the facility, which required excessive overtime that did not allow for proper controller training or adequate recovery time between shifts.