ORLANDO, Fla. — By midday Tuesday, airlines had canceled around 2,900 flights nationwide, and more than 2,500 of those cancellations came from Southwest Airlines.

>>> STREAM CHANNEL 9 EYEWITNESS NEWS LIVE <<<

United, JetBlue, Delta and American Airlines are reporting cancellation rates of between 0% and 2% on Tuesday.

Industry experts are expecting more mass cancellations in Southwest’s future, and are putting the blame on the airline’s outdate scheduling system. The U.S. Department of Transportation is now investigating.

Southwest’s union said its system has effectively lost track of where planes, pilots and flight attendants are. Experts said Southwest does not build opportunities into its schedule to hit the reset button if needed.

READ: Extreme weather across the U.S. leaves travelers stranded at Orlando International Airport

Florida State University systems sciences professor Max Etschmaier said Southwest is known for running a more shoestring operation behind the scenes to keep ticket costs down.

Etschmaier said other airlines build slack into their schedules so they can hit the recent button and avoid days of delays.

But he said there’s no one way of doing this.

READ: Arctic air moves out as Central Florida starts to warm up

“There’s no simple answer to this,” Etschmaier said. “This is a very, very complex problem, and you have to start from, really, flight by flight.”

He said because of this, he expects this won’t be the last system meltdown for Southwest.

Southwest’s website is giving passengers a place to ask for flight refunds, and the airline now says passengers can submit reasonable mean and hotel receipts for reimbursement consideration, but it does not say what the airline considers “reasonable.”

READ: Western NY death toll rises to 27 from cold, storm chaos

As for passengers who simply want to get home but can’t find an empty seat, the airline’s advice is to keep looking.

In a statement, the U.S. Department of Transportation said in part:

“The rate of cancellations and delays on Southwest Airlines is unacceptable and dramatically higher than other U.S. carriers. This afternoon, Secretary Buttigieg spoke with the CEO of Southwest Airlines and conveyed that he expects the airline to live up to the commitments it has made to passengers, including providing meal vouchers, refunds, and hotel accommodations for those experiencing significant delays or cancelations that came about as a result of Southwest’s decisions and actions. Southwest, as all airlines, is also obligated to provide a cash refund for passengers whose flights were canceled and decided not to travel.”

READ: Packed weather shelters set to close as cold conditions continue

Video: Extreme weather across the U.S. leaves travelers stranded at Orlando International Airport Hundreds of people remained stranded at the Orlando International Airport. (WFTV)

Click here to download the free WFTV news and weather apps, click here to download the WFTV Now app for your smart TV and click here to stream Channel 9 Eyewitness News live.

©2022 Cox Media Group