As Montrealer Shama Chopra boarded Northwest Airlines Flight 253 from Amsterdam to Detroit, she noticed a man lagging behind, hands on his forehead, lost in thought. He was one of the last to enter the plane.
He moved past her seat in business class into the second aisle in economy.
She didn't know the nervous man would be involved in an attempted terrorist attack on the Christmas Day flight.
It began as an uneventful journey. As everyone was readying for landing - passengers doing up their seatbelts, flight attendants making their way to their fold-out seats - the commotion started.
"I heard fireworks, I thought it was gunshots," Ms. Chopra told The Canadian Press on Saturday from her home in suburban Montreal.
"The flight attendants started screaming loudly: 'Fire, fire! Water, water!'"
Others appealed for calm, begging passengers to remain in their seats. Ms. Chopra turned and saw the man - now identified as 23-year-old Umar Farouk Abdul Mutallab - in flames.
"Then one guy behind him jumped from his chair, sat on him and, with his hands, tried to put out the flames," she said.
But he was unable to douse the fire. Passengers began passing water bottles back to help put out the blaze.
"I thought: 'We're gone now. That's it.' So I sat in my chair. What can you do but give your water bottles? So that's what everyone did. To put the flames down."
Amid the chaos, women and children were being moved to the front of the plane, she said.
"The smoke was so bad," Ms. Chopra said. "I started coughing. The children were screaming. The air hostesses were so panicked, they were almost half crying. They were saying: 'Please sit down, please, everyone stay in your chairs'."
Four people - passengers and crew - managed to wrestle the suspect down and he was brought to the front of the plane, Ms. Chopra said.
His legs and stomach were burned but he was still resisting. His captors managed to find rope, tie him up and cover him in a blanket.
"They said: 'Don't move, don't move'," she recalled. "They pushed him in a chair and they tied him up."
By that time, the plane was just minutes from landing.
Once on the ground, Ms. Chopra said, authorities boarded the flight, guns drawn, and led Mr. Mutallab of the plane.
Passengers were kept on the plane for another 30 minutes before being led into the airport and held there for five more hours. There were security agents everywhere and passengers were not even allowed to go to the bathroom without being escorted, Chopra said.
She watched the pilots as they got off the plane. She said they looked ashen and shaken.
Ms. Chopra, who had been visiting family in India, had felt ill boarding the flight in Amsterdam. Now, safely off the plane, she began vomiting. She was given a wheelchair and was allowed to stay close to the washroom.
Hours later, she was boarded a Montreal-bound flight home.
Ms. Chopra said she flies frequently and wouldn't hesitate to get on a plane again. But she would be wary about boarding another U.S. flight.
"One crazy guy can do anything," she said. "You can't go into everyone's mind."
Still, recalling how tight security seemed at the Schiphol airport in Amsterdam, she doesn't understand how Mr. Mutallab managed to get on the plane in the first place.
"I don't know how this guy entered, what more they need to do?" she asked.
Now home, Ms. Chopra gets scared when she thinks back to the incident.
"Somehow this device didn't explode," she said. "If it had exploded, we would be all gone. Finished. Two-hundred and-seventy-eight people, plus the crew."