The crash occurred while the entire flight crew were preoccupied with a burnt-out landing gear indicator light.

On December 29, 1972, Flight 401 was operated using a Lockheed L-1011 TriStar (registration N310EA), which had been delivered to the airline just a few months earlier on August 18.

[7] The flight was commanded by Captain Robert Albin "Bob" Loft, aged 55, a veteran pilot ranked fiftieth in seniority at Eastern Air Lines.

[6]: 27–29  A company employee—technical officer Angelo Donadeo, aged 47, returning to Miami from an assignment in New York City—accompanied the flight crew for the journey, but was officially an off-duty, "nonrevenue passenger".

[6]: 6 [7]: 98 Flight 401 departed New York on Friday, December 29, 1972, at 21:20 EST, with 163 passengers and thirteen crew members aboard.

[6]: 3 Loft, who was working the radio during this leg of the flight, told the tower that they would discontinue their approach to their airport and requested to enter a holding pattern.

[6]: 3  The cockpit crew removed the light assembly,[7]: 102  and Repo was dispatched to the avionics bay beneath the flight deck to check via a small porthole whether the landing gear was indeed down.

[6]: 4  In the next seventy seconds, the airplane lost only 250 ft (76 m), but this was enough to trigger the altitude warning C-chord chime located under Repo's workstation.

About 490 feet (150 m) from the wingtip's initial contact with the ground, the massive fuselage had begun to break up, scattering components from the underfloor galley, the cargo compartments, and the cabin interior.

At 820 ft (250 m) along the wreckage trail, the outer section of the starboard wing tore off, gouging a 59-foot-long (18 m) crater in the soft ground as it did so.

From this point on, the breakup of the fuselage became more extensive, scattering metal fragments, cabin fittings, and passenger seats widely.

Incongruously, not far from the roofless fuselage center section with the inner portion of the starboard wing still attached, lay a large, undamaged and fully inflated rubber dinghy, one of a number carried on the TriStar in the event of an emergency water landing.

[7]: 107–109 Robert "Bud" Marquis (1929–2008),[8] a local airboat pilot, was out frog gigging with Ray Dickinsin (1929–1988) when they witnessed the crash.

[5] Despite their own injuries, the surviving flight attendants were credited with helping other survivors and several quick-thinking actions, such as warning survivors of the danger of striking matches due to jet fuel in the swamp water, as flashlights were not part of the standard equipment on commercial airliners at the time,[10] and singing Christmas carols to keep up morale and draw the attention of rescuers.

Frank Borman, a former NASA astronaut and Eastern's senior vice president of operations, was awakened at home by a telephone call reporting a probable crash.

He accompanied three survivors on the helicopter to hospital, including a flight attendant and a passenger who lost her baby in the crash.

[6]: 6 [a] The National Transportation Safety Board (NTSB) investigation discovered that the autopilot had been inadvertently switched from altitude hold to control wheel steering (CWS) mode in pitch.

Investigators believe the autopilot switched modes when the captain accidentally leaned against the yoke while turning to speak to the flight engineer, who was sitting behind and to the right of him.

The slight forward pressure on the stick would have caused the aircraft to enter a slow descent, maintained by the CWS system.

[7]: 110 Investigation into the aircraft's autopilot showed that the force required to switch to CWS mode was different between the A and B channels (15 and 20 lbf or 65 and 90 N, respectively).

Preoccupation with a malfunction of the nose landing gear position indicating system distracted the crew's attention from the instruments and allowed the descent to go unnoticed.

[15] In the months and years following the crash, stories began circulating that numerous employees and passengers of Eastern had reported sightings of deceased crew members Loft and Repo sitting aboard other L-1011s (including, in particular, N318EA).

[21] Pieces of the plane's wreckage can also be found in Ed and Lorraine Warren's Occult Museum in Monroe, Connecticut.

[23] Fuller recounts stories of paranormal events aboard other Eastern aircraft and the belief that these were caused by equipment salvaged from the wreckage of Flight 401.

The accident and the subsequent ghost story were mentioned by Dan Aykroyd during his appearance on The Tonight Show Starring Johnny Carson on June 6, 1984.