Four people on a twin engine aircraft were unharmed after a landing gear collapsed Monday afternoon after landing at Columbia Regional Airport.

The Beechcraft Baron had arrived around 2:30 p.m. from Hook Field in Texas.

According to City of Columbia Community Relations Director Steven Sapp, the reason is still unknown as to why the aircraft’s landing gear collapsed after clearing the main runway. The incident left one prop on the plane badly damaged.

The airport was closed as Columbia Fire Department was called in to lift the plane using air bags.

One flight to Dallas Fort-Worth, American Airlines 3681, was delayed about four hours until 7:30 p.m. while crews worked to remove the aircraft.

The aircraft was towed around 6:30 p.m.