(The Hill) — A flight bound for Los Angeles was forced to make an unexpected landing on Monday when a communication breakdown led pilots to erroneously believe an attempt was being made to breach the cockpit. The confusion arose when flight attendants, unable to use the plane’s communication system, resorted to knocking on the locked cockpit door.

SkyWest flight 6569, which had departed from Eppley Airfield in Omaha, Nebraska, circled back to the airport around 7:45 p.m. local time. The Federal Aviation Administration (FAA) explained that the emergency landing was declared due to the pilots’ inability to communicate with the cabin crew.

This American Airlines flight, operated by SkyWest, had barely covered 40 miles of its journey before it returned to Omaha.

According to the FAA, the issue was traced to a malfunction of the inter-phone system, prompting the cabin crew to knock on the cockpit door to establish contact with the pilots.

While SkyWest has yet to provide a comment regarding the incident, passengers received an apology from the captain once the plane safely landed.

The captain apologized to the passengers after landing.

“We weren’t sure if something was going on with the airplane, so that’s why we’re coming back here,” the captain said. “It’s going to be a little bit. We have to figure out what’s going on.”

Video footage of the flight shows police officers boarding the plane after the emergency landing, as police vehicles approached on the tarmac.