Betty Ong - known as "Bee" to her friends - had worked for American for 14 years.
Today, with her family listening in, a government commission investigating 9/11 played a tape of that call. Ong's was the first voice on the tape.
"The cockpit is not answering. Somebody is stabbed in business class and, um, I think there is some mace," she said. "We can't breathe. I don't know, but I think we're getting hijacked."
Ong could not see everything that was happening in the front of the plane, but she had seen enough.
"Our first class galley flight attendant and our purser have been stabbed. We can't get to the cockpit. The door won't open."
American Airlines reservations officials scrambled to understand what was happening while Betty Ong patiently waited.
Ong: "Is anybody still there?"
Reservations - male: "Yes, we're still here."
Ong: "I am staying on the line as well."
Reservations - female: "Who are you, hon?"
Reservations - male: "She gave her name as Betty Ong."
American's Operations Center in Texas was alerted.
Operations: "Have they taken everyone out of first class?"
Reservations: "Yeah, she is saying that they have. They're in coach. What is going on honey? Okay. The aircraft is erratic again."
Operations: "We contacted air traffic controllers and they are going to handle this as a confirmed hijacking."
By then, however, American Airlines Flight 11 had begun a steep turn to follow the Hudson River and was soon seen cruising low and fast over the very heart of New York City.
Reservations: "Betty? Do you think we lost her? Okay, so we'll stay open. I think we might have lost her."
The point in playing the tape was apparently twofold: first to show that Betty Ong, like all flight crews that day, acted heroically. The second was to underscore one of the chief reasons the hijackers succeeded that day: because flight crews were trained to never fight back -- a policy that has since been totally rewritten.