Yellowstone River bridge collapse: Clean-up begins after Montana train derailment

Freight train carried hazardous materials including asphalt and molten sulfur

Several train cars plunge into the Yellowstone River after a bridge collapse in the US state of Montana. AP

A railway company had said a clean-up operation has begun in the US state of Montana after a freight train carrying hazardous materials derailed.

Multiple cars carrying asphalt and molten sulphur plunged into the Yellowstone River after a bridge collapsed early on Saturday.

The derailment occurred in Stillwater County, about 64km west of Billings. No injuries were reported, Montana Rail Link Andy Garland said.

Preliminary results of water and air quality did not indicate that there was any threat to the public.

“Water quality testing will continue until the clean-up is complete and at this time there are no known risks to the public drinking water,” said Kevin Stone, a representative for the Montana Department of Environmental Quality.

Water testing is being conducted by Montana Rail Link while the state's Department of Environmental Quality and the US Environmental Production Agency is overseeing it. Mr Garland said water testing will continue throughout the duration of the clean-up.

Mr Garland said the hot asphalt and sulphur solidified when mixed with the water and that they are not likely to move downstream.

“We are aware of reports of globs of asphalt appearing downriver that may be associated with the derailment and we will proactively investigate and sample this material,” Stillwater County Disaster and Emergency Services Department said in a statement.

Two additional cars contained sodium hydrogen sulphate, Montana Rail Link said, although they did not land in the river.

The cause of the bridge collapse is still under investigation.

AP contributed to this report