Oct. 21 (UPI) -- A plane made an emergency landing in Nebraska after the pilots in the cockpit lost contact with the flight attendants and heard knocking on the cockpit door.

The flight was an American Airlines flight operated by SkyWest Airlines. It took off from Omaha headed to Los Angeles but almost immediately turned around and landed 18 minutes later.

"After landing, it was determined there was a problem with the inter-phone system and the flight crew was knocking on the cockpit door," the FAA said in a statement.

"We weren't sure if something was going on with the airplane, so that's why we're coming back here. It's gonna be a little bit. We have to figure out what's going on," the captain announced after the plane landed, according to a video.

Videos of the plane on the runway after landing showed the plane surrounded by fire trucks.