Another passenger who claimed to be seated near the woman reportedly told Endress that she went to the bathroom about halfway into the 2 hours and 45 minute flight. But she wasn't attended to until the flight was due to land, when they realised a passenger was missing during the routine landing procedures.
Ross Feinstein, a spokesman for American Airlines told the StarTribune that flight attendants would not necessarily notice whether a passenger has been in a bathroom for a long time.
"If a flight attendant is made aware of a passenger in the lavatory for an extended period of time, of course a flight attendant will check on the passenger to make sure they are all right," he told the newspaper.
But the woman, identified by relatives as Theresa Hines, 48, of Carrollton, Texas, said she was travelling alone.
After the flight crew drew no response to their knocks and inquiries, the bathroom door was opened and they asked for a doctor or nurse who might be aboard, Endress recounted.
A nurse and then a doctor went to the woman's aid, and a defibrillator was employed, he told the StarTribune.
Once the plane landed, the EMTs boarded, and that's when Hines was moved off the plane and onto the jetway.
After about an hour, a tarp was put up in the jetway to shield the woman as the passengers were allowed to disembark.