American Airlines resumed flying at 5 p.m. Tuesday, following an hours-long, systemwide ground delay that affected all of its domestic and international flights and inconvenienced thousands of passengers stuck on the tarmac and in airports.
The carrier, however, warned passengers to expect continued flight delays and cancellations throughout the remainder of the day and evening.
Outages were related to the carrier's inability to access its reservation system. The technical problems were not related to the bombings in Boston.
Those who had to travel Tuesday and already were at the airport could rebook on another airline by visiting an AA agent, calling other airlines or going to the other airlines' ticket counter with their electronic ticket number.
Those who had to travel on Tuesday and were not yet at the airport could rebook through AA reservations or through another carrier and American would honor the fare difference.
Reservation change fees were waived or a full refund provided if a customer chose not to travel on Tuesday.