A panel flew off a Delta Airlines plane Sunday night, shaking the aircraft and giving passengers a look at something no one ever wants to see mid-air.

“The whole plane shook,” the description of a picture of the exposed wing’s electronics posted to Imgur read.

Officials said the panel was not necessary for the plane to land safely and it did, in fact, touch down without incident. (Image source: Imgur)

Officials said the panel was not necessary for the plane to land safely and it did, in fact, touch down without incident. (Image source: Imgur)

“All the passengers were remarkably calm,” David Watterson, who was on the plane, told ABC News. But, he noted that it was still “concerning to see a big chunk of the plane missing.”

Fortunately, the panel was not necessary for flight 2412 from Orlando, Fla., to Atlanta to land safely, Delta spokesman Anthony Black said, according to NBC News.

“The crew, knowing that, followed procedure by declaring an emergency to air traffic control as they were landing, which gave them priority clearance to land and alerted ground crews,” Black said.

ABC News reported that the flight returned to Orlando for an uneventful landing around 7:30 p.m.

Watch WSB-TV’s report about the incident:

An investigation is underway to determine why the panel came off.