Southwest Airlines flights across the country were held up Wednesday while the airline worked to fix technology problems.
Southwest began having intermittent problems with several systems after an outage.
Late Wednesday night, Southwest Airlines released the following statement:
Southwest Airlines is reducing the number of flights departing after 9:00 p.m. Central Daylight Time Wednesday evening in an effort to fully restore our system for tomorrow's operation. Flexible rebooking accommodation will be available to Customers once our systems are fully functional. Customers who are booked to travel tomorrow, Thursday, July 21, should check flight status information on Southwest.com and plan to arrive to the airport early, as longer than typical lines are likely. Our Teams are working diligently through the night to resolve issues as quickly as possible.
Southwest Airlines began experiencing intermittent performance issues earlier this afternoon with multiple technology systems as a result of an outage. Flight delays across our network have resulted in 600-700 canceled and delayed flights. Systems are gradually coming back online and we continue to move toward a normal operation. We sincerely apologize to our Customers whose travel plans have been impacted.
Updates will be posted on swamedia.com, our Southwest Facebook page and Twitter accounts.
"We are now managing flight delays across our system, with a temporary ground stop in place for those flights that have not left the gate," spokesman Brad Hawkins said in an emailed statement.
For about three hours, visitors to Southwest.com couldn't buy tickets, check in for flights, or check their flight's status. The site appeared to be working again by late afternoon.
Hawkins said that systems were gradually coming back, but that it might take time before the airline could resume normal operations.
Anxious customers tweeted to Southwest that they could not check in for flights.
Leah Boyd and her husband, Matt, were flying to Providence, Rhode Island, but were held up at the Baltimore airport for three hours by mechanical issues with two different planes.
They finally boarded a plane, but after sitting at the gate for nearly an hour passengers were asked to exit because of the technology outage, Boyd said. Then the pilots reached the end of their shifts, so passengers waited for a replacement crew.
The Boyds ended up canceling their reservations and planned to drive to Providence on Thursday instead. Leah figured it would be hard to find seats on another flight.
"I've never seen so many people in the terminal," she said. "All these people are going to be flying standby."
By 8 p.m. Central time, Southwest had canceled 17 flights, more than any other U.S. carrier, and delayed more than 600, according to tracking service FlightAware.com.
Airlines have sprawling, overlapping and complicated technology systems, and even brief outages can cause thousands of passengers to be stranded for hours.
Last October, an outage caused about 800 Southwest flights to be delayed and forced employees to issue tickets and boarding passes by hand. The airline blamed a software application, and it recovered in about a day. United Airlines and American Airlines both had computer problems last summer but fixed the problems within a day.
Dallas-based Southwest Airlines Co. carries more passengers within the United States than any airline. However, it is far smaller than American, Delta and United when international traffic is included.
WMAR Staff contributed to this story