David Miller (name changed to protect privacy), an observant Jew, was at Logan Airport getting ready to board United Flight 175. He was going to LA on an important business trip and had to make this flight. A lot depended on it.
He boarded the plane and sat down as the doors closed.
Suddenly he remembered that he had left his tefillin (phylacteries--ritual boxes with straps worn by Jewish men in prayer) in the terminal boarding area. He politely asked the stewardess if he could go back and retrieve his tefillin, which were sitting just a few feet from the gate.
She told him that once the doors closed, no one was allowed off the plane. He asked to speak to the pilot to obtain special permission, but the pilot simply restated the policy.
David was not about to lose this precious mitzvah, or let the holy tefillin get lost, so, not knowing what else to do, he started screaming at the top of his lungs, "I am going to lose my tefillin!"
The crew asked him to be quiet, but he refused. He made such a tumult that the flight crew told him that they would let him off the plane, but even though it would only take about 90 seconds to run out, grab his tefillin, and run back - they were not going to wait for him.
No matter. David was not about to lose his tefillin, even if it caused him great inconvenience or cost his business a loss.
He left the plane, never to re-board.
This was United flight #175, the second plane to reach the World Trade Center. The date was September 11 2001.
David's devotion to a mitzvah saved his life, but the consequences of his actions do not end there.
Originally, the terrorists wanted both towers struck simultaneously to maximize the explosive carnage. Later it was learned that due to David's intransigence, the takeoff was delayed, causing a space of 18 minutes between the striking of the two towers.
The delay made it possible for thousands of people to escape alive from both buildings--because one Jew would not forsake his beloved tefillin!
This story is documented in "Even in the darkest moments" by Zeev Breier.