Airlines delayed or canceled more than 10,000 U.S. flights on Wednesday after a government pilot-alerting system failure prompted the Federal Aviation Administration to halt all departures nationwide for 90 minutes.

FlightAware, an aviation tracking website, said airlines had delayed 8,783 flights and canceled 1,274 flights as of 4 p.m. ET as they continued to dig out from the ground stop that was lifted around 9 a.m. Eastern time.