WASHINGTON (WASHINGTON POST) - A passenger who was onboard Southwest Airlines flight 1380 on Tuesday (April 17) emotionally described on Thursday how he and others tried to save the woman who died when she was sucked outside the plane when one of its engines exploded in mid-air.

Ms Jennifer Riordan, a 43-year-old bank executive and mother of two from Albuquerque, was seated in row 14 when she was sucked through a 25.4-by-35.6-cm window that had been broken by pieces of the disintegrating engine, two individuals familiar with the investigation said.

Firefighter Andrew Needum, of Celina, Texas, said he heard a "loud pop", moments after flight attendants had begun to take drink orders.

Mr Needum, seated next to his father and son, turned back to see that oxygen masks had deployed in the cabin.

Mr Needum, who has been described as a hero for his efforts to save Ms Riordan, said he was helping a young woman with an infant in her lap put on their masks when he heard a commotion six or seven rows behind him.

He turned to his wife, Stephanie.

"And I looked at her eyes and she basically gave me the approval to go back there," Mr Needum told reporters at a news conference on Thursday.

"What took place back there I'm gonna leave, out of respect for her family, I'm gonna leave that alone," Mr Needum said. "I'm trained for emergency situations and it's just exactly what it was. And I felt moved to act."

When he rushed to row 14, passenger Tim McGinty was trying to pull Ms Riordan back inside the plane. Mr Needum helped Mr McGinty and they were able to pull Ms Riordan back.

A nurse began administering CPR.

As Southwest Captain Tammie Jo Shults turned on her final approach to an emergency landing at Philadelphia International Airport, she calmly described conditions on the craft to the air traffic controller.

"Southwest 1380, we're single engine," said Capt Shults, a former fighter pilot with the US Navy. "We have part of the aircraft missing, so we're going to need to slow down a bit."

She asked for medical personnel to meet the aircraft on the runway. "We've got injured passengers."

"Injured passengers, OK, and is your airplane physically on fire?" asked the air traffic controller.

"No, it's not on fire, but part of it's missing," Capt Shults said, pausing for a moment. "They said there's a hole, and, uh, someone went out."

With the plane flying at about 885km per hour, Ms Riordan probably died instantly. The cause of death was blunt impact trauma to her head, neck and torso, according to the Philadelphia medical examiner.

An individual familiar with the investigation said it is likely Ms Riordan's neck broke from the force of the airplane's speed when her head was pulled outside.

"Sitting by the window - particularly if she was leaning against it the way many people do when they're resting - when it broke the full force of the depressurisation would have sucked her right out," said the individual, who asked not to be named to speak candidly about the investigation findings.

The individual said the fact that Ms Riordan had her seat belt fastened most likely allowed passengers who reacted quickly to pull her back into the airplane.

The National Transportation Safety Board has said the principal culprit of the explosion was a fracture - most likely because of metal fatigue - of one of the 24 fan blades in the engine.

When that blade broke away at the fan's hub, it carried with it parts of the engine cowling and related engine parts.

At least one of those parts broke the acrylic of the window where Ms Riordan was seated.

NTSB Chairman Robert Sumwalt said on Wednesday that investigators found no pieces of the window inside the cabin.

"If you can possibly imagine going through the window of an airplane at about 600 miles per hour and hitting either the fuselage or the wing with your body, with your face, then I think I can probably tell you there was significant trauma," Ms Peggy Phillips, the nurse who performed CPR on Ms Riordan told ABC.

At times, Mr Needum cried as he talked about Ms Riordan.

"She had two kids and a loving husband and community around her that loved her," he said. "My heart is broken for them. I just pray that they find comfort, that they find healing whatever that may be and however they seek it."

Ms Stephanie Needum, his wife, said that after the episode had ended, Capt Shults spoke with the passengers.

"She reassured us that in her 32 years of flying that her oxygen masks had never come down," she said. "She comforted everyone. She's an amazing person."