Photo/Illutration An Akita Nairiku Jukan Railway train car lies overturned after derailing and falling from a bridge in Kita-Akita, Akita Prefecture, on Dec. 12. (Yasuhiro Kumabe)

KITA-AKITA, Akita Prefecture--A fallen tree caused a single-car train to derail and plunge off a bridge in northern Japan early on Dec. 12, injuring the driver.

No passengers were on board.

The accident occurred at 5:07 a.m. on the Akita Nairiku Line in Kita-Akita.

The train was traveling between Arase and Kayakusa stations when it hit the tree on the tracks. The impact knocked the train off the rails, and it fell about 4 to 5 meters from the bridge, according to the transport ministry.

Railway staff became concerned when the train failed to arrive at its final destination, Kakunodate Station, at its scheduled time of 6:16 a.m. They were unable to contact the driver.

They alerted police around 6:50 a.m. after discovering the overturned vehicle.

The driver in his 50s was rescued from the wreckage and hospitalized with a jaw injury.

His injuries are not considered life-threatening, and he remained conscious and was able to speak, according to the Kita-Akita Police Station.

Police said the crash site was located on a gentle curve.

The Japan Transport Safety Board dispatched two railway accident investigators to the scene.