Authorities in Savonlinna are investigating a fatal car crash that claimed the lives of three young adults over the weekend as aggravated traffic endangerment and manslaughter.

Three people were killed and a fourth was seriously injured after the car they were in crashed into a road sign at around 6am on Saturday. There were three men and one woman in the vehicle at the time of the violent collision.

The car was split apart by the impact. Three of the people were thrown from the vehicle and one was found in the back seat, wearing a seat belt. The victim in the car was still alive when rescue personnel arrived, but later died in the hospital.

The collision came to the attention of police when people near the scene reported a loud sound along the road, concerned about what might have happened.

The vehicle's back tyres were very worn out and there was water on the road by the accident scene. Police suspect that high situational speed may have been a factor in the collision as well.

Authorities are also looking into whether alcohol or drugs played a role in the crash.