HOUSTON, Texas (KTRK) -- Southwest Airlines is apologizing to thousands of frustrated passengers after the airline canceled nearly 2,000 flights over the weekend and the problem lingered into Monday.
By Monday afternoon, Southwest had canceled more than 360 flights and nearly 1,200 others were delayed.
Nineteen flights originating from Houston's Hobby Airport were among the cancellations Monday, according to FlightAware, and 31 flights had been delayed.
Bush Intercontinental Airport only had about 11 cancellations and 63 flights delayed as of Monday afternoon.
The airline released an updated statement Monday about the ongoing issues.
"Southwest Airlines extends a tremendous apology to our Customers and Employees for the flight cancellations and delays which occurred over the weekend and on Monday.
On Friday evening, the airline ended the day with numerous cancellations, primarily created by weather and other external constraints, which left aircraft and Crews out of pre-planned positions to operate our schedule on Saturday. Unfortunately, the out-of-place aircraft and continued strain on our Crew resources created additional cancelations across our point-to-point network that cascaded throughout the weekend and into Monday."
Airline representatives went on to say the problems were not related to any employee demonstrations.
The Federal Aviation Administration said there have been no major air traffic control issues since Friday. Other airlines also haven't had to cancel nearly as many flights as Southwest.
Southwest has struggled all summer with high numbers of delayed and canceled flights. In August it announced it was trimming its September schedule by 27 flights a day, or less than 1%, and 162 flights a day, or 4.5% of the schedule, from early October through Nov. 5.
The White House has pushed airlines to adopt vaccine mandates because they get paid under federal contracts, making them subject to President Joe Biden's order that federal contractors require vaccination among employees.
United Airlines was the first major U.S. carrier to announce a vaccination requirement. Southwest had remained silent even after Biden announced his order for federal contractors and large employers. Finally last week Southwest told employees they must be fully vaccinated by Dec. 8 to keep their jobs. Workers can ask to skip the shots for medical or religious reasons.
As the scope of Southwest's operational meltdown became clear over the weekend, the pilots' union also denied reports that pilots were conducting a sickout or slowdown to protest the vaccine mandate. The Southwest Airlines Pilots Association said it "has not authorized, and will not condone, any job action."
The union offered another explanation: It said Southwest's operation "has become brittle and subject to massive failures under the slightest pressure" because of a lack of support from the company. The union complained about the "already strained relationship" between it and the company.
Savanthi Syth, an airlines analyst for Raymond James, said the weekend problems will increase Southwest' costs and worsen the company's strained relations with unions.
The Associated Press contributed to this report.
For updates on the Southwest Airlines issues, follow Charly Edsitty on Facebook, Twitter and Instagram.
Southwest Airlines flight cancellations continue into Monday, frustrating customers
More TOP STORIES News