Power outage grounds US Airways' computer ops

Service is back to normal - or at least close to it - on US Airways this morning after many of its flights were grounded or delayed.

A power outage in Phoenix shut down the airline's computer system, causing a cascade of problems nationwide.

Passengers couldn't make reservations or check in online.

The cause of the outage has not been determined.

Officials at the Tempe-based carrier couldn't immediately say how many flights or passengers were affected.

Airline spokeswoman Tina Swail says some computer systems were back online by Friday evening and the carrier was "working to restore operational order."

In a statement the airline strongly encouraged customers to check their flight's status online before arriving at the airport or by calling US Airways Reservations at (800) 428-4322.