Panic and shock after a train derailed in northeastern Taiwan on Sunday in the island's worst rail disaster in more than three decades.

At least 18 people were killed and 175 injured when all eight cars ran off the tracks in Yilan County... an area popular among tourists.

Four carriages overturned in the crash.

Hundreds of rescuers scrambled to tend to the injured passengers.

Military personnel combed through the wreckage to search for survivors.

Officials say an American citizen was among the injured.

Authorities are checking to see if other foreigners were on board.

It's unclear at this point what caused the crash -- the island's deadliest train tragedy since 1981 when 30 people were killed in a collision in northern Taiwan.