Wichit Police were notified of the incident at about 9:30pm by Wichit Municipality and dispatched officers and investigators to a commercial building on Thepanusorn Rd in Moo 2, Wichit.
Police found the injured man, believed to be aged between 30 and 35, on the ground outside the building. His identity and nationality had not been confirmed at the time of reporting.
According to witnesses, the man had been behaving erratically while apparently intoxicated. He climbed onto the roof of the two-storey building, where he was seen walking around before lying down on the roof.
Witnesses also told police that he threw bottles and other objects from the roof onto the street below on two occasions, causing alarm among nearby residents.
The man later lost his balance and fell from the roof, suffering serious injuries.
Rescue workers from Wichit Municipality provided first aid at the scene before transporting him to Vachira Phuket Hospital for emergency treatment.
Investigating officers, accompanied by Wichit Village Chief Orawara Anekthammapinit, examined the scene, photographed evidence and documented the area as part of the investigation.
Police said they are reviewing CCTV footage, interviewing witnesses and working to establish the man’s identity. Officers will also monitor his condition in hospital and coordinate with relevant agencies as the investigation continues.
No damage to nearby property was reported.