(CNN) — Southwest Airlines said it was “resuming normal operations” and investigating the cause of technical issues that paused departing flights Tuesday afternoon.
The outage was the second technical issue in less than 24 hours, and the airline said it is “in the process of investigating the root cause of each event to determine the reason behind the technology issue.”
The Federal Aviation Administration said it “issued a temporary nationwide ground stop at the request of Southwest Airlines while the company resolved a reservation computer issue.”
Delta and Alaska Airlines also reported computer issues Monday that affected their ability to sell tickets.
Passengers across the country took to social media to express their frustration and demand answers after the issue left some people grounded, stranded and stuck on planes.
Southwest said the technical issue Monday prevented the transmission of weather information that is required to safely operate their aircraft.
“While the vendor worked to restore connectivity, we implemented a ground stop to protect the safety of our crews and customers,” the statement said.
Southwest said it was working to get all passengers to their destinations as quickly as possible.
Chris Martin, who was traveling on Monday, told CNN he was delayed for over two hours on a Southwest Airlines flight from San Jose, California, to Austin, Texas.
“Lining up to board now, apparently they are releasing the weather paperwork city by city. This was a 5:55pm departure, now 8:17pm out here,” Martin told CNN. “Twenty-two flights showing on the board delayed or canceled.”
Jason Goran, another passenger who was traveling from San Diego, California, to Houston, said he sat on the plane for two hours because of the weather system outage.
Goran said the flight was scheduled to take off at 5:50 p.m. PT. By the time he spoke with CNN, it was 8:17 p.m. PT.
“It feels like we are about to take off,” he said at the time. “They called us back to the plane but we haven’t pushed back yet.”
Patrick Miller said after boarding his flight from Phoenix to Portland, Oregon, passengers had to deplane and then reboard. “From boarding to deplaning, it (took) two hours,” Miller told CNN.
People were losing their patience because of the delay, he said.
Other passengers, such as Ryan Cesaitis, said they were able to take off and land, but ended up stuck on their planes as issues continued to plague the airline.
The ability to check in for flights was not affected, according to the statement.
Alaska Airlines also experienced issues Monday. In a tweet to a customer, the airline said that its “booking page is down. Our team is working hard to get this resolved.”
CNN reached out to Alaska Airlines for comment but has not yet heard back.
CNN’s Gregory Wallace contributed to this report.