At least three people have died and several more suffered injures after an Amtrak train derailed in north-central Montana.
The National Transportation Safety Board said late Saturday it will investigate the incident.
The Seattle-bound Empire Builder train had about 141 passengers and 16 crew aboard when eight cars derailed near the town of Joplin at about 4:00 pm MDT (2200 GMT), Amtrak said in a statement.
People trapped aboard soon after the derailment have all been taken off the train, said the official at the Liberty County Sheriff's Office, who spoke on condition of anonymity.
There were multiple injuries but no final count, the official added. A social media user posted photos of train cars on their side after the incident and other damaged train cars.
The cause of the incident was not immediately clear.
The 10-car train with two locomotives had departed from Chicago.
Amtrak said Empire Builder trains originating on Saturday are cancelled between Minot, North Dakota, and Shelby, Montana, while on Sunday the westbound Empire Builder train will terminate in Minneapolis and an eastbound Empire Builder train will originate in Minneapolis.