Montana train derailment
© Matthew Brown/AP Photo
Several freight train cars carrying hazardous materials plunged into the Yellowstone River in Montana on Saturday during a bridge collapse, officials said.

The incident occurred in Stillwater County, approximately 60 miles from Montana's largest city, Billings. At least seven freight cars fell into the river when the bridge collapsed, according to a statement from the Stillwater County Disaster and Emergency Services. The water supply downstream was shut down temporarily while officials assessed the full scale of the event, The Associated Press reported. Montana Rail Link, the company that operated the train, said no injuries were reported and the train operators were safe.

The area around the derailment is sparsely populated, and the river flows away from Yellowstone National Park, located about 110 miles away. However, the cars that fell into the river contained hot asphalt and molten sulfur, Stillwater County officials said. It was initially unclear if the train cars had been compromised, but AP reported that a yellow substance was seen emerging from at least one of the cars sitting in the river.

While the asphalt and sulfur both solidify quickly when exposed to cooler temperatures, Stillwater County said that two other cars that derailed had contained sodium hydrogen sulfate. This is a toxic substance, and "ingestion or skin contact with [the] material may cause severe injury or death," the National Institutes of Health reported. However, officials said neither of the cars containing sodium hydrogen sulfate had entered the river.

Multiple state and federal agencies were on the scene, CBS News reported, including Federal Railroad Administration officials. U.S. Transportation Secretary Pete Buttigieg tweeted that he'd spoken to Montana Gov. Greg Gianforte (R) to "offer support following a derailment," adding that additional federal resources will be available. "Residents concerned about potential impacts should follow information and instructions from local authorities," Buttigieg said.