ANKARA (Reuters) – Four people were killed in southwest Turkey on Sunday when an ambulance helicopter collided with a hospital building and crashed into the ground.

The helicopter was taking off from the Mugla Training and Research Hospital, carrying two pilots, a doctor and another medical worker, the health ministry said in a statement.

Mugla’s regional governor, Idris Akbiyik, told reporters the helicopter first hit the fourth floor of the hospital building before crashing into the ground. No one inside the building or on the ground was hurt. The cause of the accident, which took place during heavy fog, was being investigated.

Footage from the site showed debris from the crash scattered around the area outside the hospital building, with several ambulances and emergency teams at the scene.