A Delta Air Lines flight from Salt Lake City to Washington made an emergency landing in Denver on Thursday after the plane's window shattered.

The Federal Aviation Administration said in a statement that Delta Flight 760 made an emergency landing at Denver International Airport after the crew declared an emergency. The F.A.A. will conduct an investigation into the cause of the crack.

The plane, a Boeing 757, had a maintenance issue mid-flight, but did not offer information about when the windshield started to crack or why.

Ms. Long said in a statement on Saturday that the flight crew diverted into Denver out of an abundance of caution.

A photo of a cockpit posted on the social networking site shows a windshield lined with multiple cracks but still in its frame.

One of the passengers on the flight said that the plane would be landing in Denver about 90 minutes after takeoff.

The passenger, Rachel Wright, told KUTV that they were diverted to Denver in about 10 minutes.

She said that the passengers were told to remain calm.

Ms. Wright told KUTV that being told to stay calm made them feel a little panicky.

John Cox, a former US Airways captain, wrote in a USA Today column about aircraft in 2019. In the event of a shattering or rupturing of the glass, it is possible to hold full pressure if the other is lost or broken.

He said that heating problems are usually the cause of the cracks in the cockpit window. Mr. Cox has heard of pilots who have cracked their windshields at cruising altitude, but he believes that it is more likely to happen when a plane is climbing.

Airplanes are designed to remain safe if a window cracks.