Holiday travelers flying with American Airlines experienced widespread Christmas Eve disruptions on Tuesday after the Federal Aviation Administration (FAA) announced that the airline had grounded all flights nationwide.The ground stop, which took place on one of the busiest travel days of the year, was lifted shortly after it was announcedsometime before 8 a.m. ETbut it appeared to cause delays well into the morning.On social media, travelers expressed their frustration, with American Airlines explaining on X that it was working to resolve the issue. Rest assured, our team is working on getting you back on track as soon as possible, the airline said in one reply.Earlier, American Airlines had said the stoppage was related to a technical issue. An advisory from the Philadelphia International Airport, meanwhile, alluded to computer issues.The airline later released a statement blaming a vendor technology issue and adding, That issue has been resolved and flights have resumed, ABC News reported.Fast Company has reached out to American Airlines for more details and will update this post when we hear back.According to data from AAA and Inrix, some 7.8 million U.S. travelers are expected to fly during the holiday period.This story is developing