A helicopter crash on Sunday claimed the lives of four people after it struck the fourth floor of a hospital in southwestern Turkey, provincial authorities reported.

The victims included two pilots, a doctor, and an employee on board the helicopter. The incident occurred during take-off from the rooftop of a hospital in Mugla, en route to Antalya, according to provincial governor Idris Akbiyik.

"The helicopter fell to the ground after having struck the fourth storey of a hospital during take-off," Akbiyik explained, adding that "intense fog" was the primary cause of the crash.

Eyewitness reports and footage from Turkish broadcaster NTV showed the helicopter drifting in dense fog shortly after take-off before crashing into a vacant field near the hospital.

Authorities have launched an investigation to determine additional factors contributing to the accident.

This tragedy follows another fatal incident in Turkey’s Isparta province less than two weeks ago, where six soldiers lost their lives in a military training exercise involving two helicopters.