NANTUCKET, Mass. (AP) — A Cape Air flight departing from the Massachusetts island of Nantucket returned safely after part of the main cabin door opened shortly after takeoff, an alarming midair incident that prompted the crew to turn back.

The aircraft remained stable and continued operating normally, and no injuries were reported, a Cape Air spokesperson told news outlets.

A passenger video shared on Instagram appears to show the upper portion of the cabin door ajar during the flight, with open sky and ocean visible through the gap. The footage, filmed from inside the small aircraft, shows the door frame and window area partially open as the plane flies at altitude, while passengers remain seated nearby.

The flight had departed from Nantucket Memorial Airport on Monday when the upper portion of the main cabin door opened, the airline said. The crew returned the plane to the airport, where it landed without further incident. The aircraft has been taken out of service for evaluation, and the airline said it is following established safety procedures and will take any necessary actions based on its findings.

The island of Nantucket sits roughly 30 miles (48 kilometers) off Massachusetts’ southern coast and is a popular summer destination accessible primarily by air and ferry.