On September 25, 1978, a catastrophic accident occurred in Los Angeles when Pacific Southwest Airlines Flight 182, a Boeing 727, collided with a Cessna 172 over the North Park residential neighborhood. The collision resulted in 144 fatalities: 135 aboard Flight 182, two in the Cessna, and seven residents on the ground. Investigation revealed a sequence of human errors and miscommunication within the air traffic control tower contributed to the accident. Visibility was good that day.