CLEVELAND (AP) — The Latest on a cracked window on a Southwest Airlines jet (all times local): 
 
 1:30 p.m. 
 
 Aviation experts say the slightest defect or micro-crack in a plane window can cause cracks like the one that forced a Southwest Airlines jet to land in Cleveland. 
 
 A Southwest spokeswoman says Flight 957 traveling from Chicago to New Jersey never lost cabin pressure and that the pilots didn't declare an emergency before landing Wednesday morning. 
 
 There were no reports of injuries. 
 
 Airline consultant Robert Mann says windows are periodically polished to remove the formation of tiny cracks in the acrylic windows from exposure to chemicals and the sun's rays. 
 
 He says the pilots were right to make a quick landing. 
 
 Anthony Roman, a commercial pilot and flight instructor based in New York, says problems with windows should be detected during regular inspections and maintenance. 
 
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 12:45 p.m. 
 
 A Southwest Airlines spokeswoman says a plane forced to land in Cleveland because of a cracked window never lost cabin pressure. 
 
 Spokeswoman Brandy King also says the pilots didn't declare an emergency before landing Wednesday morning. 
 
 There were no reports of injuries after Flight 957 traveling from Chicago to New Jersey landed safely. 
 
 Southwest says there were no other mechanical problems with the plane that has been taken out of service. 
 
 The emergency landing comes two weeks after a Southwest Airlines plane made an emergency landing in Philadelphia after an engine exploded and a blew out a window in a deadly accident. 
 
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 12 p.m. 
 
 A Southwest Airlines plane flying from Chicago to New Jersey has been forced to land in Cleveland after one of its windows cracked. 
 
 There were no reports of injuries after Flight 957 landed safely on Wednesday morning. 
 
 Dallas-based Southwest says that the plane diverted to Cleveland for a maintenance review after the issue on one of the multiple layers of window pane. 
 
 The emergency landing comes two weeks after a Southwest Airlines plane made an emergency landing in Philadelphia after an engine explosion and a blown out window. 
 
 A woman who was partly sucked out of that window was killed. ||||| The engine on a Southwest Airlines plane is inspected as it sits on the runway at the Philadelphia International Airport after it made an emergency landing in Philadelphia, Tuesday, April 17, 2018. (Amanda... (Associated Press) 
 
 The engine on a Southwest Airlines plane is inspected as it sits on the runway at the Philadelphia International Airport after it made an emergency landing in Philadelphia, Tuesday, April 17, 2018. (Amanda Bourman via AP) (Associated Press) 
 
 PHILADELPHIA (AP) — A preliminary examination of the blown jet engine of the Southwest Airlines plane that set off a terrifying chain of events and left a businesswoman hanging half outside a shattered window showed evidence of "metal fatigue," according to the National Transportation Safety Board. 
 
 Passengers scrambled to save the woman from getting sucked out the window that had been smashed by debris. She later died, and seven others were injured. 
 
 The pilots of the twin-engine Boeing 737 bound from New York to Dallas with 149 people aboard took it into a rapid descent Tuesday and made an emergency landing in Philadelphia. Oxygen masks dropped from the ceiling and passengers said their prayers and braced for impact. 
 
 "I just remember holding my husband's hand, and we just prayed and prayed and prayed," said passenger Amanda Bourman, of New York. 
 
 The dead woman was identified as Jennifer Riordan, a Wells Fargo bank executive and mother of two from Albuquerque, New Mexico. The seven other victims suffered minor injuries. 
 
 The National Transportation Safety Board sent a team of investigators to Philadelphia. 
 
 In a late night news conference, NTSB chairman Robert Sumwalt said one of the engine's fan blades was separated and missing. The blade was separated at the point where it would come into the hub and there was evidence of metal fatigue, Sumwalt said. 
 
 The engine will be examined further to understand what caused the failure. The investigation is expected to take 12 to 15 months. 
 
 Photos of the plane on the tarmac showed a missing window and a chunk gone from the left engine, including part of its cover. A piece of the engine covering was later found in Bernville, Pennsylvania, about 70 miles (112 kilometers) west of Philadelphia, Sumwalt said. 
 
 As a precaution, Southwest said Tuesday night that it would inspect similar engines in its fleet over the next 30 days. 
 
 Passengers praised one of the pilots, Tammie Jo Shults, for her cool-headed handling of the emergency. The former Navy pilot was at the controls when the plane made the emergency landing. She walked through the aisle and talked with passengers to make sure they were OK after the aircraft touched down. 
 
 "She has nerves of steel. That lady, I applaud her," said Alfred Tumlinson, of Corpus Christi, Texas. "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." 
 
 In a recording of conversations between the cockpit and air traffic controllers, an unidentified crew member reported that there was a hole in the plane and "someone went out." 
 
 Tumlinson said a man in a cowboy hat rushed forward a few rows to grab the woman and pull her back in. 
 
 "She was out of the plane. He couldn't do it by himself, so another gentleman came over and helped to get her back in the plane, and they got her," he said. 
 
 Passengers struggled to somehow plug the hole while giving the badly injured woman CPR. 
 
 As the plane came in for a landing, everyone started yelling to brace for impact, then clapped after the aircraft touched down safely, Bourman said. 
 
 Southwest CEO Gary Kelly said there were no problems with the plane or its engine when it was inspected on Sunday. 
 
 The jet's CFM56-7B engines were made by CFM International, jointly owned by General Electric and Safran Aircraft Engines of France. CFM said in a statement that the CFM56-7B has had "an outstanding safety and reliability record" since its debut in 1997. 
 
 Last year, the engine maker and the Federal Aviation Administration instructed airlines to make ultrasonic inspections of the fan blades of engines like those on the Southwest jet. The FAA said the move was prompted by a report of a fan blade failing and hurling debris. A Southwest spokeswoman said the engine that failed Tuesday was not covered by that directive, but the airline announced it would speed up ultrasonic inspections of fan blades of its CFM56-series engines anyway. 
 
 "There's a ring around the engine that is meant to contain the engine pieces when this happens," said John Goglia, a former NTSB member. "In this case it didn't. That's going to be a big focal point for the NTSB — why didn't (the ring) do its job?" 
 
 In 2016, a Southwest Boeing 737-700 blew an engine as it flew from New Orleans to Orlando, Florida, and shrapnel tore a 5-by-16-inch hole just above the wing. The plane landed safely. The NTSB said a fan blade had broken off, apparently because of metal fatigue. 
 
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 Koenig reported from Dallas. Associated Press writers Kristen de Groot and Claudia Lauer in Philadelphia; Susan Montoya in Albuquerque, New Mexico; and Matthew Barakat in Washington, contributed to this story, along with AP researchers Monika Mathur and Jennifer Farrar. ||||| It is the stuff of movies, but on Tuesday, it became all too real for passengers on Southwest Airlines flight 1380, who said a woman was partially sucked out of the plane’s window after it was blown out when one of the aircraft’s engine exploded. 
 
 [One person is dead after engine fails on Southwest flight, forcing emergency landing] 
 
 The woman, Jennifer Riordan of Albuquerque, was seated in Row 14, the same row as the missing window, federal investigators said Wednesday. Witnesses said passengers and flight attendants pulled her back. 
 
 The flight, which was headed to Dallas from New York’s La Guardia Airport, made an emergency landing at Philadelphia International Airport. 
 
 Riordan, a Wells Fargo Bank executive and mother of two, died later at a Philadelphia-area hospital. Seven other passengers were injured. Federal officials said Riordan’s death was the first passenger fatality on a U.S. carrier since 2009. 
 
 The Philadelphia Department of Public Health said Wednesday night that Riordan died of blunt-impact trauma to her head, neck and torso. 
 
 “The listed cause of death seems consistent with what we’ve heard in media reports,” department spokesman James Garrow said, though he could not confirm the nature of her death. “The cause that we’re listing and have written on the death certificate sounds consistent with what has been reported,” he said, but he could not say whether the injuries were caused by “the fuselage or the air or the window or debris.” 
 
 [The story of the pilot who calmly landed the Southwest Airlines flight] 
 
 Robert Sumwalt, chairman of the National Transportation Safety Board, said investigators are aware of reports from passengers that Riordan was nearly sucked out of the plane, but that “we have not corroborated that ourselves.” He did say that there were no other holes in the cabin. Investigators also did not find any pieces of the window inside the plane. 
 
 The very idea that a passenger could be sucked out of an airplane midflight has rattled many travelers. Such incidents are rare but have happened. For example, in 1988, an Aloha Airlines flight attendant was pulled to her death after a hole opened in the roof during a flight to Honolulu from Hilo, Hawaii. 
 
 It’s all about air pressure, which varies depending on location. At sea level, atmospheric pressure is about 14.7 psi (pounds per square inch), Thomas Anthony, director of the University of Southern California’s aviation security program, told the Verge. But at an airplane’s cruising altitude, about 33,000 feet, it drops to about 4 psi. That is why the higher you go, the more difficult it is to breathe. The air gets thinner. It’s the reason climbers on Mount Everest must carry oxygen with them. 
 
 Aircraft cabins are pressurized to keep passengers comfortable and alive at high altitudes, said Jim Gregory, a professor of aeronautical engineering and director of the Aerospace Research Center at Ohio State University. 
 
 Without that pressurization, Gregory said: “Every passenger would suffer from hypoxia [a condition in which a person’s body doesn’t get enough oxygen] within a minute or less.” 
 
 Gregory said that the pressure level inside the Southwest cabin was probably about 11 psi, compared with 4 psi outside. While those numbers may not seem that far apart — the difference in pressure could be up to seven pounds per square inch. That could translate to roughly 600 pounds of force acting on each of the plane’s windows, which is why once the window was blown out, the resulting suction would be enough to pull a passenger from a seat. 
 
 [Weather radar detects engine debris from Southwest Airlines Flight 1380] 
 
 “When the window ruptures, you have those two pressure levels trying to equalize,” said Ladd Sanger, an aviation attorney and licensed airplane and helicopter pilot. “The pressure inside the airplane is escaping out that hole to attempt to equalize, which is why it’s creating that suction and pulling from inside the aircraft.” 
 
 Those conditions explain how a passenger could be partially pulled into a small airplane window. And the difficulty of pulling them back in. 
 
 “You think about the pressure differential,” Sanger said. “It’s about somewhere between six and eight times.” 
 
 Gregory said while incidents like Tuesday’s are rare, they are an important reminder that travelers need to pay attention to the preflight safety briefings. That starts with the basics: wearing your seat belt and knowing how to properly wear the oxygen mask. Video from the Southwest flight showed people grabbing their masks and putting them over their mouths, but not their noses. 
 
 As the flight attendants always say during the safety briefings: 
 
 “In the event of a decompression, an oxygen mask will automatically appear in front of you. To start the flow of oxygen, pull the mask towards you. Place it firmly over your nose and mouth, secure the elastic band behind your head, and breathe normally. Although the bag does not inflate, oxygen is flowing to the mask. If you are traveling with a child or someone who requires assistance, secure your mask on first, and then assist the other person. Keep your mask on until a uniformed crew member advises you to remove it.” 
 
 Ashley Halsey contributed to this report.
– A Southwest Airlines plane flying from Chicago to New Jersey was forced to land in Cleveland on Wednesday after one of its windows cracked. The exit-aisle window cracked mid-flight, reports the New York Times, but the cabin never lost pressure as only one of the window's many plexiglass layers was affected. (You can see images here.) There were no reports of injuries after Flight 957 landed safely at Cleveland's Hopkins International Airport, and no emergency was declared. Aviation experts tell the AP the slightest defect or micro-crack in a plane window can cause cracks like this one. Airline consultant Robert Mann says windows are periodically polished to remove the formation of tiny cracks in the acrylic windows from exposure to chemicals and the sun's rays. "The flight landed uneventfully in Cleveland," Southwest said in a statement. "The aircraft has been taken out of service, and our local Cleveland Employees are working diligently to accommodate the 76 customers on a new aircraft to Newark." The incident comes two weeks after a Southwest Airlines plane made an emergency landing in Philadelphia after an engine explosion and a blown out window. A woman who was partly sucked out of that window was killed.