On May 11, 1996, the DC-9 aircraft on this route began a normal ascent, then reported smoke in the cockpit and passenger areas of the aircraft. Air traffic control advised flight 592 to turn around after its pilot declared an emergency and demanded an emergency landing at the closest possible airport. The plane disappeared from radar before reaching any airport, and was found to have crashed in uninhabited territory inside the Florida Everglades. All 110 passengers and crew died in the crash.
Recovery of the aircraft and victims was extremely difficult due to the location of the crash. The nearest road of any kind was more than a quarter mile away from the crash scene, and the location of the crash itself could have been summarized as a deep water swamp with a bedrock base. The DC-9 shattered on impact with the bedrock; very few large portions of the airplane remained. Sawgrass, alligators, and risk of bacterial infection from cuts plagued searchers involved in the recovery effort.
The NTSB investigation eventually determined that the source of the fire that downed flight 592 was a cargo compartment below the passenger portion of the plane. The cargo compartment's fire suppression amounted to a no-air recycling environment, so a standard fire would simply run out of air and burn itself out.
The circumstances of this fire were unique, however. It was determined that the fire was caused by the firing of expired chemical oxygen generators placed in the cargo compartment in a box marked 'Airplane parts' by ValuJet's maintenance contractor, SabreTech. The generators should not have been shipped in this manner in the first place, since they were hazardous materials. Making the matter worse was the fact that the firing pins for the oxygen canisters were not properly protected with plastic sleeves to prevent an unintended firing of the canister.
Chemical oxygen generators, when fired, produce oxygen. As a byproduct of the chemical reaction, they also produce a great quantity of heat. These two pieces together were sufficient to not only start an accidental fire, but produce the oxygen to keep the fire burning at an extremely high temperature. An pop and jolt traced in the air traffic control tape was attributed to an aircraft tire (shipped with the oxygen generators) exploding in the high temperature fire.
The NTSB placed fault for ValuJet Flight 592 in three places: on ValuJet, for not being aware of what its contractor (SabreTech) was doing; on SabreTech, for illegally transporting dangerous materials aboard a commercial aircraft, improperly labeling them, and not providing safety equipment to ship them; and on the FAA for not requiring active fire suppression equipment in this cargo compartment. SabreTech was convicted of criminal charges, the first time this had happened to an aviation company in connection with an airplane crash in America. The bad publicity quickly drove SabreTech out of business entirely.
The disaster hurt the credibility of the ValuJet airline so much that what remained of it was forced to change its name to Airtran.