David Burke, an employee of USAir, had been on unpaid leave following an investiagtion into his theft of $68 from an airline fund. In a hearing on December 7, he was dismissed from his job even after he pleaded for leniency. As he left his office, he was told to have a nice day, for which he replied, "I intend to have a very nice day."

Burke then purchased a ticket on Pacific Southwest Airlines Flight 1771, a daily flight from Los Angeles, California to San Francisco. Using his USAir credentials, he was able to bypass security armed with a loaded .44 Magnum pistol. Before he got onto the plane at Los Angeles International Airport, he left a note reading: "It's kind of ironical, isn't it? I asked for leniency for my family, remember? Well, I got none, and now you'll get none."

As the plane was cruising in the air at 29,000 feet, Burke took out his handgun and shot someone, as the cockpit recorder later confirmed. He then opened the cockpit door. A female, presumed to be a flight attendant, told the cockpit crew that "we have a problem." The Captain replied with "what kind of problem?" Burke then appeared at the cockpit door and announced "I'm the problem," simultaneously firing two more shots that probably killed the pilots.

Several seconds later, the recorder picked up increasing windscreen noise as the airplane pitched down and began to accelerate. A final gunshot is heard as Burke fatally shoots himself. The plane then descened until 13,000 feet, when, while traveling at Mach 1.2, the aircraft broke apart and crashed in a farmer's field in the Santa Anna Hills near Templeton, California.