Air Canada said it would reach out via email or text to let customers know if their flights are canceled. The cancellations on Thursday included some long-haul overseas flights. By the end of Friday, the airline expects to cancel 500 flights.

Katherine Twaddle, who came to Canada from Britain for the Stratford theatre festival, said she is avoiding accepting a refund from Air Canada for her cancelled flight back to London. She worries it would forfeit her right to a rebooking.