A policeman and two women were killed and another man seriously hurt when their car was hit by a train at a crossing in Hua Hin in the early hours of Thursday.
The crash occurred at the Soi Hua Hin 94 crossing in Hua Hin about 4am, police said.
There were three dead people in the overturned white car - the driver, a policeman from Hua Hin police station, and two women passengers. A seriously injured man also trapped in the wreck was rushed to Hua Hin Hospital.
Police said the four people were returning home from a party.
The crossing was controlled by automatic barriers. Nakhon Si Thammarat-Bangkok express train No 86 was leaving nearby Hua Hin railway station for the South as the car approached the crossing.
The car driver appeared not to have noticed the approaching train and drove around the barrier and onto the track.
Police were investigating.
