Scores of flights at Canadian airports arriving from and heading to the American east coast have been cancelled due to Hurricane Irene.
More than 80 Saturday flights at Toronto's Pearson International Airport involving eastern U.S. cities including Washington, Philadelphia, New York, Boston and Raleigh, N.C., are called off.
U.S. flights at airports in Ottawa, Montreal and Halifax are also cancelled.
Air Canada said flights at almost two dozen airports stretching from Newfoundland to North Carolina might be disrupted as the storm races up the east coast.
Hurricane Irene touched down in North Carolina Saturday morning, while more than two million people in east coast states have been ordered evacuated.
The Canadian Hurricane Centre said Hurricane Irene will affect eastern Canada beginning Sunday and into early Monday.
In New York City, the nation's largest subway system was beginning to shut down Saturday and the typically bustling city became unusually quiet as the first rain from Hurricane Irene fell on Manhattan.
It was the first time the city has shut down the entire subway system because of a natural disaster. Final subway and bus runs started at noon, and it would take about eight hours before the entire transit system was shuttered, city officials said.