Hundreds of Southwest flights were delayed Wednesday after the airline was hit with technical issues.
The trouble started when a "system outage" led to a nationwide ground stop for all Southwest flights that lasted for just over an hour.
The company said in a statement that an early-afternoon outage impacted "multiple technology systems." After the ground stop was lifted, flights were left flights backlogged.
"We expect to continue our move toward a normal operation, but believe it will take time," Southwest said in a statement. The airline declined to say what caused the system outage.
Dozens of fliers took to Twitter to complain about the delays. Some said they were aboard flights held on the runway.
"I love @SouthwestAir but I don't love wasting my PTO on the Tarmac," one user wrote.
About 450 Southwest flights were delayed Wednesday as of about 5 p.m., according to FlightStats, though it's not clear how many of those delays were due to the technical glitch. At that same time, 261 domestic United Airlines flights and 278 American Airlines flights were delayed.
Customers also reported problems accessing the airline's website and mobile app, which prevented them from booking flights or checking in for an upcoming trip.
Downdetector counted more than 3,000 social media posts complaining about the issues beginning around 2:30 p.m. ET.
The airline's airport kiosks and southwest.com Were not available for check-in or booking.
Check flights St. Louis Lambert International Airport.
Southwest Airlines statement:
"Southwest Airlines began experiencing intermittent performance issues earlier this afternoon with multiple technology systems as a result of an outage. We continue to manage significant flight delays across our system. We apologize to our Customers whose travel plans are impacted. We have a Team of experts working diligently to fully resolve the technical issues and their efforts have systems gradually coming back online. We expect to continue our move toward a normal operation but believe it will take time. Updates will be posted on swamedia.com, our Southwest Facebook page and Twitter accounts."