Emily Brown
Almost 100 people died in what remains to be one of the worst air disasters in South Florida history, and it all came down to a lightbulb worth just $12.
It was the evening of 29 December, 1972 when 163 passengers and 13 crewmembers boarded Eastern Airlines flight 401 to travel from New York's JFK to Florida's Miami International Airport (MIA).
For the majority of the time, the flight was an uneventful one, with Captain Robert Loft, First Officer Albert Stockstill, and Flight Engineer Donald Repo successfully navigating the flight to the skies above Florida.
Ready to descend to the runway of MIA, the pilots moved the landing gear into position so they could land safely.
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But when they did, they realized the green light which indicated the gear was locked into place did not light up.
The pilots contacted the control tower at MIA, who instructed them to maintain an altitude of 2,000 feet before attempting to land again once they'd figured out the issue.
The three men in charge of the plane engaged its autopilot system and set about trying to figure out why the light was not coming on.
And in the dark night, they struggled to determine whether the issue was with the landing gear itself.
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In a transcript from the radio, one said: "I can't see it, it's pitch dark and I throw the little light, I get, ah, nothing."
A few moments later, the staff at the control tower heard the first officer say: "We did something to the altitude."
Loft replied, "What?," before Stockstill asked: "We're still at two thousand right?"
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As they'd attempted to figure out why the light was not coming on, the pilots didn't realize that the plane's autopilot feature had disengaged.
The plane had dropped rapidly, causing the pilot to say: "Hey, what's happening here?"
Seconds later, Flight 401 crashed into swamplands of the Florida Everglades.
Bud Marquis, who was hunting frogs with a friend at the time, witnessed the bright flash as the plane hit the ground, and was the first to arrive at the scene.
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"I'm one person in the midst of all this," Marquis told NBC News in 2007. "I'm no doctor. I didn't know what to do."
A total of 94 passengers and five crew members died at the scene, while the rest of the survivors struggled in the swamp water, which was now contaminated with jet fuel.
Dozens of people were taken to hospital after the crash, with another two people losing their lives in the aftermath.
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An investigation into the crash determined that the pilots had been preoccupied by the light, and therefore hadn't noticed the plane descending.
The investigation determined that the issue was not with the landing gear after all.
Instead, it was simply that the lightbulb used to indicate it was locked in place, which was worth about $12, had burned out.
The cause was reported as 'the failure of the flight crew to monitor the flight instruments during the final 4 minutes of flight, and to detect an unexpected descent soon enough to prevent impact with the ground', according to the National Transportation Safety Board (NTSB).
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"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," it continued.
The NTSB added that it was possible the altitude hold function on the autopilot had been accidentally disengaged, causing the plane to descend while the pilots were trying to figure out the issue with the light.
A number of safety enhancements were developed after the plane crash, including a system which alerts pilots if an aircraft is in immediate danger of flying into the ground or an obstacle.
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Eastern Airlines continued to operate for almost two decades, eventually ceasing its operations early in 1991.