Southwest Plane Makes Emergency Landing After Cabin Window Breaks in Flight

A Southwest Airlines flight made an emergency landing on Wednesday after a pane in one of the cabin windows was damaged in flight.

The Federal Aviation Administration said it was investigating what caused the window, which was on an exit row, to break. The plane, which was traveling from Chicago to Newark, made an emergency landing in Cleveland at 11:45 a.m., although the damage did not affect the pressure inside the plane, Southwest said.

The airline said that the Boeing 737 had been taken out of service so that maintenance teams could investigate, and that the 76 passengers aboard the flight would be flown to Newark on another plane.

Airplane windows generally have multiple plexiglass layers, and the airline said the damage had only affected one layer.

The episode comes just two weeks after a more serious one involved another Boeing 737 operated by Southwest. In that instance, a fan blade in one of the plane’s engines broke apart mid-flight, sending debris into the fuselage and through a cabin window.

As the cabin rapidly lost pressure, the passenger sitting next to the window, Jennifer Riordan, was partially pulled out. The plane, which had departed from La Guardia Airport in New York and was bound for Dallas made an emergency landing in Philadelphia. Ms. Riordan was later declared dead.

The F.A.A. has ordered inspections of the engine type involved in that episode.