4:30 PM PT -- The one fatality is the woman who was sucked out of the window, TMZ has learned. Passengers said Jennifer Riordan's entire upper body was outside and she was bleeding profusely before others were able to pull her back inside the cabin. They performed CPR on her for up to 20 minutes.
1:18 PM PT -- One person is confirmed dead, according to a rep for the National Transportation Safety Board.
Southwest Airlines passengers were remarkably calm moments after one of the plane's engines was shredded by something -- despite the fact one of them was almost sucked out of the cabin.
The images from the Tuesday morning flight -- which made an emergency landing in Philadelphia -- are pretty terrifying. Shrapnel from the left wing turbine apparently flew back and shattered a cabin window, and witnesses say, if not for the aid of her fellow passengers ... one woman would have been sucked through the opening.