This story originally appeared on 6abc.
A computer system at the Federal Aviation Administration went down early Wednesday morning, leading to a nationwide ground stop on all domestic departures.
That pause was lifted at 9 a.m., and operations have been gradually resuming. Still, the problem impacted thousands of flights across the country.
Hundreds of those impacted flights were out of Philadelphia International Airport. So far, 174 flights had been delayed and another 55 were canceled.
The FAA computer system that went down is known as NOTAM – Notice to Air Messages. It alerts pilots of issues that could impact their flights.
Without the critical information, the FAA made the rare move to call that nationwide ground stop.
“They were like, all the flights are going to be delayed,” said Selena Vazquez of Mayfair.
“We just got the update that it changed. Now our 10:45 is now a 12:30,” said Carley Rettbeg of Voorhees. “We’ll get there eventually.”
Passengers at PHL started to see the departure screens change to “delayed” and “canceled” around 7 a.m.
With no one able to fly out, things quickly backed up inside.
“The line to check in my bag was the longest I’ve ever been in on any flight, and I fly several times every year. So that was a little shocking,” said William Mualem of Deptford.
But as the FAA allowed flights to resume at 9 a.m. things started to clear up, but there could be lasting issues throughout the day.
So what caused the computer outage?
There is an investigation unfolding now and the president has been briefed. The White House doesn’t believe it was a cyberattack.