Airlines have canceled hundreds of flights scheduled for Friday due to the winter storm expected to make travel hazardous due to snow and freezing rain.

At Hartsfield-Jackson International Airport, Delta Air Lines’ largest hub, there were more than 1,200 flights canceled for Friday as of about 5:30 p.m., according to FlightAware.com.

Atlanta-based Delta canceled more than 800 of its flights scheduled for Friday in Atlanta, including Delta Connection regional carrier flights. That’s more than 45% of its flights scheduled for the day at the world’s busiest airport, FlightAware data show. Delta said its Atlanta hub was hit with a “worse-than-expected mix of winter weather” and said additional disruptions were possible “throughout the weekend.” More than 60 flights scheduled for Saturday at Hartsfield-Jackson had been canceled by late Friday afternoon.

Tay Williams was trying to get to Los Angeles to catch a cruise but his flight got cancelled after he arrived at the airport Friday morning. He planned to sleep in the terminal to try to catch his rebooked flight Saturday morning. “We have no choice. And it’s snowing outside, so we don’t want to get back on the road like that,” Williams said.

In addition to the storm, operations were also disrupted after a Delta plane aborted a takeoff from Hartsfield-Jackson due to an engine issue just after 9 a.m. Friday morning. Passengers evacuated from the plane via evacuation slides.

Combined, the storm and the evacuation brought flights at Hartsfield-Jackson to a halt, with all five runways temporarily closed for more than two hours, according to Delta.

While a runway was open in the morning during the snowstorm, it closed to traffic after the Delta aborted takeoff and evacuation.

Another runway reopened in the afternoon for traffic to restart.

A ground stop Friday was extended until 2 p.m. for Delta flights, with another ground stop later in the afternoon until 6:30 p.m. according to the Federal Aviation Administration’s website. And, a ground delay program was put in place for Delta flights until around 10 p.m., with departures to Atlanta delayed an average of more than three hours.

As the day wore on, Delta canceled hundreds more flights scheduled for Friday.

The airline urged customers to check their flight status on its website or app.

David Hall was trying Friday to get home to Cincinnati, but he was already facing at least a six hour delay, he said Friday afternoon.

“I just would have liked to have known. I mean, if it’s canceled, that’s fine. I’ll go get a hotel and I’ll fly tomorrow, but I’ve got to get it changed so I can get out,” Hall said. “Otherwise I’m getting a rental car and I’ll drive home. It’s seven hours. But my biggest problem is, I’m not driving through Atlanta right now with all the weather and the roads.”

Most parts of metro Atlanta could get up to a quarter-inch of ice, according to the National Weather Service, which issued a winter storm warning, in effect until 7 a.m. Saturday. Gov. Brian Kemp issued a state of emergency ahead of the severe winter weather.

Delta CEO Ed Bastian told The Atlanta Journal-Constitution Thursday afternoon that the company didn’t “know anything different than you know” about the weather but that it’s prepared and will run a reduced schedule Friday. “There will be proactive cancellations and thinning, that’s what we always do in advance of a major event to keep customers out of the airport and try to give them as much notice in advance,” he said.

However, other airlines canceled flights earlier Thursday.

Southwest Airlines, the second-largest carrier at Hartsfield-Jackson, canceled more than 120 flights scheduled for Friday in Atlanta, according to FlightAware. That’s the majority of the flights Dallas-based Southwest had planned to operate in and out of Atlanta on Friday.

Frontier Airlines canceled nearly all of its flights scheduled at Hartsfield-Jackson for Friday. The ultra low-cost carrier canceled more than 70 of its Friday flights going to or from Atlanta, according to FlightAware.

Spirit Airlines canceled more than 45 of its Friday flights in Atlanta, most of its schedule for the day at Hartsfield-Jackson. United Airlines and American Airlines each canceled more than 20 of its Atlanta flights, more than half of what the carriers had scheduled at Hartsfield-Jackson for Friday.

Delta said those whose flights are canceled will be automatically rebooked or can seek alternate flights by contacting Delta at the airport, by phone, or by messaging through the Fly Delta app.

Those whose flights are canceled or delayed by three hours or more for domestic flights can request to be rebooked, or if they choose not to fly they are entitled to a refund for a flight they did not take.

The Atlanta disruptions come after the storm already caused havoc in Dallas. Airlines canceled more than 1,600 flight cancellations at Dallas-Fort Worth International Airport and Dallas Love Field on Thursday.

Airlines on Wednesday warned of the travel disruptions and issued waivers to give travelers around the Southeast more flexibility to change their flight bookings in advance of the storm.