A 17-year-old boy was killed when the car he was driving hit a telegraph pole.
The crash happened on the A362 at Buckland Dinham, near Frome, at about 2215 GMT on Tuesday.
The car is thought to have left the road after a right-hand bend. Fire crews freed the boy from the Mini, but he was declared dead at the scene.
The road was closed for about four hours. Police are appealing for witnesses.