passenger jet end and a major scare midflight. It was a southwest jet flying from Chicago to Newark, when a passenger window suddenly cracked. The 737 forced to divert to Cleveland, and, of course, this comes just two weeks after the other southwest flight, when a woman was sucked out of the plane and pulled back in. She did not survive. Here's ABC's Linzie Janis. Reporter: Tonight, another scare on a southwest flight. Passengers terrified after this window cracked midair. There was a loud pop. Something cracked the win doeshgs and it was cracked through. Reporter: Flight number 957 took off from Chicago's midway airport for Newark just after 9:00 A.M. But less than an hour later, the pilot diverting to Cleveland, Ohio. The crack on the outer window pane not deep enough to cause depressurization inside the plane. This is what we call a precautionary emergency. In other words, it's not an immediate threat, because there's no loss of cabin pressurization. But any time if you have any part of the airplane compromised, including a window, you want to get down as soon as you reasonably can. Reporter: The 737 and its 76 passengers landing safely. Everybody breathe, we are almost there. Reporter: Just two weeks after passenger Jennifer Riordan was nearly sucked out of a similar southwest plane after shrapnel from an engine busted through the window next to her. The mother of two dying from her injuries. Tonight, a southwest spokeswoman saying the decision to divert today's flight was made "For maintenance review of one of the multiple layers of a window pane. Pane. About Linzie Janis joining us tonight. Southwest says the window was inspected last month, Linzie? Reporter: That's right, David. Southwest says it's too early to say what caused this window to crack, but the FAA is also investigating, and it says this is rare, happening 26 times since Boeing has been flying the 737. David? Linzie, thank you. And there is new video just