DETROIT -- The holiday travel season is always busy and this year it's been marked by heavy weather in several parts of the country.
Now, it's being further complicated by tighter security after a failed Christmas Day attempt to blow up a Detroit-bound plane.
Airports worldwide have tightened security in the aftermath.
Passengers are getting extra pat-downs before boarding and being instructed to stay in their seats without blankets or pillows for the last hour of the flight.
Air Canada also says that passengers won't be allowed access to carry-on baggage or to have any items on their laps during the last hour.
Passenger and law enforcement officials accounts describe Umar Farouk Abdulmutallab leaving his seating for 20 minutes to go to the bathroom.
He returned complaining of an upset stomach and covered himself with a blanket.
After that, passengers say they heard a pop like a firecracker and saw flames.