An engine exploded on a Southwest jet enroute from New York to Dallas Tuesday, killing a mother of two, injuring seven other passengers and causing panic in the skies until the plane made an emergency landing at Philadelphia International Airport.
In a Wednesday afternoon press conference at the airport, the National Transportation Safety Board offered some answers, but still left many questions.
"I know that people want answers right away," NTSB chairman Robert Sumwalt said. "We will do a very methodical investigation."
Here is new information that emerged Wednesday:
Here are other highlights from Wednesday, as additional information came in about the flight and emergency landing:
The leading edge of the left wing was "banged up pretty good" from the explosion of the left engine, Sumwalt said at his afternoon press conference.
The agency has received multiple reports of people finding pieces of the exterior part of that engine on the ground. The pieces were intended to keep wires from being exposed, Sumwalt said.
When the engine exploded, the aircraft began a "left roll of about 41 degrees of bank angle" — something that "would be alarming," given that an aircraft that size rarely exceeds 25 degrees of bank angle, Sumwalt said. After a few seconds, the pilot leveled the wings.
The plane touched down in Philadelphia at 190 mph, also faster than the speed at which a 737 usually lands (around 155 mph), Sumwalt said. This was due to the plane having to land with a lesser flap setting than is typical, he said.
A passenger's video posted on Instagram shows flight attendants trying to calm passengers, telling them to relax and breathe, before the flight made in emergency landing in Philadelphia.
Authorities have collected a piece of the jet that fell to the ground when the plane's left engine exploded.
The metal cowl that surrounds the engine landed in a field on state game land in Bernville, Berks County, about 75 miles northwest of Philadelphia.
A spokeswoman for Southwest Airlines said Wednesday a maintenance recommendation from the manufacturer of the plane's engine that addressed problems with fan blades would not have applied to the engine involved in Tuesday's mid-air failure.
In 2017, the engine maker, CFM International, issued a bulletin recommending the fan blades on CFM56 series engines receive special attention after 15,000 cycles in service without an engine shop visit, which amounts to about four years of regular use. That bulletin was prompted by an August 2016 incident eerily similar to the one Tuesday. In that incident, an engine identical to the one that failed Tuesday also lost a fan blade, causing an engine failure that threw debris into the plane's fuselage. In the 2016 engine failure, however, no debris entered the passenger cabin and a window did not shatter.
That incident remains under investigation by the National Transportation Safety Board.
"No, the engine was not subject to the bulletin released last year," said Brandy King, the Southwest spokeswoman.
She did not specify as to whether the bulletin didn't apply because the engine had not logged 15,000 cycles since its last maintenance or some other reason. She also didn't provide information on when the engine was last inspected.
Last August, the Federal Aviation Administration proposed a directive that would have mandated the type of testing the CFM bulletin recommended, an ultrasonic inspection that would reveal flaws in metal parts. That proposal is still going through the FAA's approval process.
When the engine explosion caused a window to break and left Riordan partially hanging outside it, a man in a cowboy hat and a firefighter pulled her back inside, according to USA Today. The newspaper identified the cowboy as Tim McGinty and the firefighter as Andrew Needum.
A retired nurse than tried to resuscitate Riordan, McGinty said. After the plane landed, she was taken to an area hospital, where she died Tuesday afternoon.
The FBI is assisting the National Transportation Safety Board in collecting pieces of the Southwest Airlines jet that fell to the ground when the plane's left engine exploded in the skies over Pennsylvania on Tuesday
One team has been sent to recover the metal cowl that surrounds the engine that landed in a field on state game land in Bernville, Berks County, about 75 miles northwest of Philadelphia.
Anyone who finds debris from the plane is asked to call the FBI's Allentown field office at 610-433-6488.
The National Transportation Safety Board, which is investigating the deadly engine failure aboard Southwest flight 1380, has scheduled a briefing for 4:30 p.m, by its chairman, Robert Sumwalt, at Philadelphia International Airport, where the damaged plane is being stored in a hangar.
The investigation into the cause will likely focus on a fan blade that broke off from one of the Boeing 737's two engines, Sumwalt said at a briefing Tuesday night. The blade, one of 24 that bring air into the craft's turbo fan engine, broke near where it connected to the engine's hub and there is evidence of metal fatigue near the break.
The NTSB, in the meantime, released video of investigator's initial examination of the plane.
After the plane was rocked from the explosion there was a rush of air, there was a commotion a few rows behind her and a call for anyone who knew CPR, Phillips said.
Phillips rushed to the row where a window had blown out and found two passengers trying to pull Riordan, a bank executive from New Mexico, back into the plane.
Once Riordan was inside, Phillips said, she and an EMT administered CPR until the plane landed in Philadelphia 20 minutes later and Philadelphia Fire Department medics boarded the aircraft.
"If you can possibly imagine going through the window of an airplane at about 600 miles an 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," Phillips said.
In a recording of the call between Flight 1380 and Air Traffic Control, the pilot, identified by her family as former U.S. Navy flyer Tammie Jo Shults, calmly reports her plane is in trouble.
ATC: Injured passengers, okay, and are you, is your airplane physically plane on fire?
Pilot: Not fire, not fire. But part of it's missing. They said there's a hole and, uh, someone went out.
Shults' ability to remain calm as she navigated the damaged aircraft to safety earned her praise from passengers following the traumatic ordeal.
"She has nerves of steel," Alfred Tumlinson told the Associated Press. "That lady, I applaud her. I'm going to send her a Christmas card — I'm going to tell you that — with a gift certificate for getting me on the ground. She was awesome."
>>READ MORE: In their words: Passengers describe "freak accident"
Another passenger, Diana McBride Self, wrote that Shults came back to personally speak with passengers once the plane was safely on the tarmac in Philadelphia. Self thanked Shults for her "knowledge, guidance and bravery in a traumatic situation."
"God bless her and all the crew," Self wrote.