SALT LAKE CITY, Utah – Pilots on a Delta Airlines flight from Salt Lake City to Washington, D.C. have made an emergency landing in Denver after the cockpit windshield shattered at more than 30,000 feet.

The crew repeatedly asked the passengers to remain calm until they landed.

“They’d use the loudspeaker and say the windshield is broken and we’ll be turning over to Denver in about 10 minutes,” Rachel Wright, one of the 198 passengers on the plane, told KUTV.

A photo of the windshield taken by a passenger shows cracked glass that did not fall off its frame. Commercial airline pilots said passenger planes’ windshields can be two inches, about 5 centimeters thick, with several layers of glass, the station said.

The crew announced the diversion about 90 minutes after the plane reached cruising altitude, which is more than 30,000 feet, passengers said.

“They kept saying everybody keep calm, stay calm, and we were quiet, so they told us to keep quiet while we were quiet, that made us feel a little bit panicked,” Wright said.

Passengers were able to see the broken glass as soon as they landed in Denver.

Passengers of a flight from San Juan to Orlando experienced moments of panic as they were about to take off in Puerto Rico, only one passenger testified in Telemundo 31 news.

I’m really good at playing ‘what if?’ “And so my mind goes to what could have happened, worst case scenario, and I am grateful,” Wright said. “It could have been really bad. It could have been very different.”

Another passenger, Kirk Knowlton, took a photo and wrote on Twitter that the crew announced that the windshield shattered spontaneously.

Delta spokesman Anthony Black confirmed a “crack in the windshield” on Friday but said the cause had not yet been determined.

“Out of extreme caution, the flight crew shifted to Denver and the plane landed routinely. Our team worked quickly to accommodate customers on a new plane and we sincerely apologize for the delay and inconvenience in their travel plans.”

The passengers boarded a new plane in Denver and continued on to Washington. Wright praised Delta for landing the plane safely and said the airline was very comfortable.

“I have never been more grateful to spend three extra hours at the airport,” Wright said.