NASHVILLE (REUTERS) - A Southwest Airlines airplane flying to Phoenix was forced to land at Nashville airport shortly after take-off because of a bird strike, a Southwest spokesman said on Wednesday (April 18).

"The captain in command declared an emergency and safely landed the flight," the spokesman said, adding that the aircraft had been taken out of service for maintenance review.

On Tuesday, a Southwest flight with 149 people aboard was forced into an emergency landing and one passenger was killed after an engine exploded in mid-air.

Flight 1380 had taken off from New York and was heading to Dallas when it was forced to divert to Philadelphia about 20 minutes after take-off.

The engine on the 737 plane's left side threw off shrapnel when it blew apart, shattering a window and causing rapid cabin depressurisation that nearly pulled a female passenger through the hole, according to witness accounts.

Another passenger was taken to a hospital in critical condition and seven people were treated for minor injuries at the scene, Philadelphia Fire Department spokesman Kathy Matheson said.

An early review of Tuesday's failed Southwest engine found preliminary evidence of metal fatigue where a fan blade had broken off, Robert Sumwalt, chairman of the US National Transportation Safety Board (NTSB), told reporters on Tuesday.

Southwest said it was speeding up inspections of all related engines, which it expected to complete within 30 days.