Witnesses said the barriers at the level crossing were lowered when the car drove on to the track, a Network Rail spokesman said:
There are 45 people on board, comprising 37 passengers and eight train crew.
The train has not derailed and no passengers or crew were injured. The car is badly damaged and is under the leading power car.
The train driver and First Great Western staff have given a statement to British Transport Police that the barriers were lowered and the car was seen to drive on to the crossing.
– British Transport Police spokesman
Shortly before 6.30am this morning BTP was called to reports of a car having been struck by a train at Athelney automatic half barrier level crossing.
The train involved is the 0546 Exeter to London Paddington service. The train has not been derailed and there are no reports of any injuries to anyone on board.
The car is trapped under the front of the train and services are currently stopped in the area.
There was one person in the car who has been pronounced dead at the scene. An investigation is under way to establish the full circumstances leading up to the incident.
British Transport Police have confirmed that one person has died after a train hit a car on a level crossing in Somerset. It happened near Athelney, which is on the line between Taunton and Castle Cary.
There were no reports of any passengers on the train being injured in the crash.
The car is trapped under the front of the train and services are stopped in the area. First Great Western is operating replacement buses between Taunton and Westbury.