The NTSB has released its preliminary report on an incident involving a medical helicopter where a door came off in flight.

It happened on January 29 during a flight operated by Air Methods from Cabell Huntington Hospital to Three Rivers Hospital in Louisa, Ky.

The NTSB report says the left rear entry door flew off why the helicopter was over Shoals, in Wayne County. The helicopter then landed safely at Tri-State Airport.

Only the pilot and two nurse were onboard during the incident. There were no injuries.

The is no word why the door came off.