A major winter storm in the Northeast U.S. caused thousands of flight cancellations and delays on Sunday.

There were more than 1,450 canceled flights and around 2,100 flights were delayed, according to flight-tracking website FlightAware.com as of Sunday afternoon.

Multiple states, which included Massachusetts, New York, Rhode Island, Connecticut, Maine, New Jersey, Delaware, and Maryland, were under winter storm warnings over the weekend. Some states were under a state of emergency warning.

“An East Coast blizzard dropped one to over 2 feet of snow along the coast. Now, cold weather will hold a grip on the Mid-Atlantic today and tonight," the National Weather Service Middle Atlantic River Forecast Center tweeted Sunday.

Parts of Massachusetts and New York saw the worst of it. Boston's Logan International Airport and New York's John F. Kennedy and LaGuardia airports had the most affected flights.

Airlines like Delta, JetBlue and United issued waivers to travelers.

"Delta's meteorology team in the airline's operation and customer center will continue to monitor the winter weather and make tactical adjustments as needed," Delta said.