Southwest Flight 1380 made a dramatic emergency landing in Philadelphia on Tuesday afternoon after an engine malfunctioned mid-flight and a piece of shrapnel broke a window. One passenger was sucked toward the open window as passengers pulled her back and performed CPR. She died Tuesday afternoon at a Philadelphia hospital.

About 20 minutes after takeoff from New York's LaGuardia Airport, a blade from the engine of a Boeing 737-700 separated from the engine and smashed a hole in the aircraft. In a press conference, National Transportation Safety Board chairman Robert Sumwalt said there was evidence of “metal fatigue” at the point of the engine where the blade meets the hub.

The woman killed was Jennifer Riordan, an executive at Wells Fargo, in New Mexico, and a mother of two.

This was the first fatal incident on a U.S. passenger airline since 2009.

Seven passengers were treated for minor injuries at the scene. There were 144 passengers and five crew members onboard the flight.

Tammie Jo Shults piloted the aircraft to the ground, calmly alerting air traffic control “We have a part of the aircraft missing.” Over the course of five minutes, the plane dropped altitude from 31,684 feet to about 10,000 feet.

“The pilot was a veteran of the Navy,” passenger Kathy Farnan told CNN. "She had 32 years in — a woman. And she was very good.” Fellow passengers praised the pilot’s technical skill and professionalism after the landing.

The NTSB and the Federal Aviation Administration (FAA) have launched investigations into the incident. The NTSB has received the flight data recorder and voice cockpit recorder from the aircraft. Investigations could last up to 15 months.

Last month, a Southwest flight made an emergency landing in New Mexico after smoke was reported in the cabin. Two people were hospitalized.

Southwest announced that it will examine engines in its fleet for signs of similar fatigue over the next 30 days.