From the NY Post:
A JFK shuttle train that had just undergone preventive maintenance lost two doors just before picking up its first passengers [Friday], sources said.
As the AirTrain pulled into the Lefferts Boulevard stop at 3:30 a.m., the two doors swung off their hinges. One careened onto the tracks and the other jammed into the platform.
"This is very troubling," said an airport source. "[Had] it happened when the train was crowded, people would have fallen out -- and they'd now be dead."
No one was aboard the computerized two-car shuttle -- which carries no conductor or motorman.
One of the broken doors, affixed to the outside of the cars, became "embedded into the concrete platform like a knife into a birthday cake," said a source.
An alarm sounded, but the train -- minus the two doors -- barreled on to the Howard Beach station, sources said.
Once there, it was taken out of service -- but staff didn't notify Port Authority officials until 6 a.m., sources said.
The potential tragedy -- and what caused it -- was under investigation last night, prompting one source to say, "They're reviewing it to see why it occurred, but all indications are that there was a problem in the maintenance yard."