A snowstorm grounded thousands of flights in some of Europe's busiest airports on Monday, stranding thousands of passengers.
Schiphol Amsterdam Airport said a third of flights have been canceled on Monday while Brussels Airport warned of numerous cancellations.
On Sunday, a total of 2,542 flights were canceled to and from France, the U.K., Germany, Belgium and the Netherlands and an additional 1,034 flights to and from airports in those countries were canceled on Monday, according to FlightAware, a flight-tracking platform.
The cancellations began after a snowstorm hit London. Delays and cancellations spilled into Monday. British Airways said it had reduced its Monday schedule. The airline's hub is London's Heathrow Airport, Europe's busiest. The carrier blamed the backup on low temperatures, requiring it to de-ice "every individual aircraft before it departs."
The delays continued because airline crews were not in place in the wake of the delays, according to a travel notice on Heathrow's website.
British Airways and Heathrow asked passengers to check the status of their flights and not to come to the airport if their flights are canceled, in an effort to avoid overcrowding.
The airline did not immediately return a request for comment on how many flights were canceled or diverted to other airports.
It was unclear how much the fallout of the storm will cost British Airways and other airlines. On Twitter, BA told some passengers it would provide hotel vouchers worth 200 pounds ($270).
Passengers took to Twitter to complain
Extensive flights delays or cancellations tend to snowball because cabin crew and aircraft are not in place for the following scheduled flights. Airlines sometimes cancel flights ahead of time when bad weather is in the forecast so they are not forced to deal with swarms of stranded travelers. Grounded planes also mean there is a lack of space at gates for inbound flights.
The airline is waiving ticket-change fees for travelers booked through Monday if they can travel no later than Dec. 18. American Airlines, a partner of British Airways, is also offering fee waivers for travelers booked to and from London.
Wintry weather over the weekend prompted cancellations on the other side of Atlantic as well. Delta Air Lines said it canceled 375 flights after a winter storm hit Atlanta, the airline's hub and the busiest airport in the world. By Sunday, the airline's operations were running normally, it said.