The National Transportation Safety Board on Wednesday was inspecting the wrecked engine of a Southwest Airlines Co jet that blew up in mid-air, killing a passenger in the first deadly US commercial airline accident in nine years.
The engine explosion, which occurred about 20 minutes after the Dallas-bound Southwest Flight 1380 with 149 on board took off from New York's LaGuardia Airport, sent pieces of shrapnel flying, including one that shattered a window near the plane's left wing, killing bank executive Jennifer Riordan, 43.
An NTSB inspection crew pored over the Boeing 737-700 and its CFM56 engine, made by a partnership of France's Safran and General Electric. It was the second time that style of engine had failed on a Southwest jet in the past two years, prompting airlines around the world to step up inspections.
Passengers described scenes of panic as a piece of shrapnel from the engine shattered a window on the aircraft, almost sucking a female passenger out. Witnesses speaking with Philadelphia media identified Riordan as the passenger nearly sucked out the window.
Videos posed on social media showed passengers grabbing for oxygen masks and screaming as the plane, piloted by 56-year-old Tammie Jo Shults, a former fighter pilot for the US Navy, prepared for its descent into Philadelphia.
"All I could think of in that moment was, I need to communicate with my loved ones," passenger Marty Martinez told ABC's Good Morning America on Wednesday. During the incident, he logged on to the plane's in-flight WiFi service to send messages to his family.
"I thought, these are my last few moments on Earth and I want people to know what happened," said Martinez, who live-streamed the plane's descent into Philadelphia on Facebook.
Southwest Airlines experienced an unrelated safety incident early on Wednesday when a Phoenix-bound flight was forced to land at Nashville airport shortly after takeoff because of bird strike.
The airline said it would inspect the fan blades of CFM56 engines on all of its 737 jets within 30 days. Minimal flight disruptions may result, it said.
NTSB Chairman Robert Sumwalt said on Tuesday at the Philadelphia airport that a preliminary investigation found an engine fan blade missing, having apparently broken off, and that there was metal fatigue at the point where it would normally be attached.
Pieces of the engine including its cowling - the smooth metal exterior that covers its inner workings - were found about 60 miles (97 km) away from Philadelphia airport, Sumwalt said.
Sumwalt said the investigation could take 12 to 15 months to complete. NTSB officials said they would next brief the media on their investigation at 4:30 pm ET.
In August 2016, a Southwest flight made a safe emergency landing in Pensacola, Florida, after a fan blade separated from the same type of engine and debris ripped a hole above the left wing. That incident prompted the US Federal Aviation Administration to propose last year that similar fan blades undergo ultrasonic inspections and be replaced if they failed.
Riordan's death was the first in a US commercial aviation accident since 2009, according to NTSB statistics.
Riordan was a Wells Fargo banking executive and well-known community volunteer from Albuquerque, New Mexico, according to a Wells Fargo official, who spoke on condition of anonymity. 
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