Local police speculated the accident took place because the driver of the double-decker bus with a raised roof, which was chartered by Bangkok-Pattaya Hospital to transport its staff on a trip, was not familiar with the winding roads in the park area.

Four people died instantly at the scene, including hospital executive Khanuengnit Weetheesathokkij, the only victim identified so far. Three others were pronounced dead at a local hospital. Whether the bus driver is among the dead or the injured was not confirmed.

Police said the casualty figures could have been higher had the bus not become lodged in a large bamboo nest before it hit the ground after it plunged from the road 100 metres above.