BILLINGS, Montana – At least seven cars from a freight train tumbled into the Yellowstone River in the US state of Montana on Saturday after a derailment and a bridge collapse, causing asphalt and molten sulphur cargo to spill into the water, the authorities said.
Officials were investigating whether the derailment or the bridge collapse happened first, as well as how much of the cargo had spread into the river.
What led up to the derailment was not immediately known, officials said.
The train cars, operated by Montana Rail Link, derailed around 6.45am local time (8.45pm Singapore time) as they headed west in Stillwater County, the county’s Disaster and Emergency Services Department said on Facebook.
Mr Andy Garland, a Montana Rail Link spokesman, said no one was injured.
Mr Garland said that two cars were carrying sodium hydrogen sulfate, but neither had entered the water nor been breached.
Three cars of hot asphalt and four cars of molten sulphur were in the river, officials said. Both substances were described as “slow moving”.
Mr David Stamey, the chief of emergency services in Stillwater County, said by phone that both spilled substances solidify quickly in the water.
That means the potential harmful effects to the environment could be limited, especially if the spread is restricted, he said.
Ten rail cars in total derailed, Mr Stamey said.
The derailment happened between Reed Point and Columbus, in an area about an hour west of Billings.
Referring to the cars, the Stillwater County Sheriff’s Office said that in a “great stroke of luck, none contained oil”.
Officials said there was no expected hazardous materials impact to the towns in the county.
The Yellowstone County Disaster and Emergency Services Department said there had been no “negative impacts” as at early Saturday afternoon.
Video of the scene showed the collapsed bridge with rail cars peeking above the flowing water.
It was not immediately clear when the bridge was constructed or when it was last inspected.
Mr Garland said Montana Rail Link was “committed to addressing any potential impacts to the area as a result of this incident and working to understand the reasons behind the accident”.