international airport today. a threat led to a flight being grounded and a startled passenger being pulled right off the play. as nbc s jay gray reports, the suspected terrorist was actually an innocent man who had no idea what was going on. reporter: the warning came just after 7:00 this morning. it was alleged that a made, and a name was given, would attempt to get onto an airplane en route somewhere this texas with a dangerous or hazardous substance. that name was christopher shell, a passengers from phipp to dallas. he posted this picture online just before takeoff. 30 minutes into the trip, the plane was ordered it turn around. at it landed, the jet was moved to a locate where armed officers, shell was taken off the plane in handcuffs. we checked him and his carry-on luggage and determined he was not in the possession of anything dangerous, hazardous our illegal. reporter: as fbi agents questioned shell, it became clear he was not part of any criminal plot,