The fatalities were confirmed by the Liberty County Sheriff’s Department and Amtrak.
Amtrak was working with local authorities to "transport injured passengers" and "safely evacuate all other passengers," Amtrak spokesman Jason Abrams said in a statement to Fox News.
The statement read:
"We are deeply saddened to learn local authorities are now confirming that three people have lost their lives as a result of this accident. There are also reported injuries among the passengers and crew members travelling on the train. Amtrak is working with the local authorities to transport those who were injured to medical care, and to safely evacuate everyone else at the scene."
The incident happened around 4 p.m. MT when Empire Builder train 7/27 derailed near Joplin, Mont. with approximately 146 passengers and 16 crew members on board. The train has two locomotives and 10 cars, seven of which derailed, Abrams said.
Images from the derailment scene, which were shared on social media, show train cars tipped over and dozens of people surrounding the aftermath. The derailment occurred on the Empire Builder line, which runs between Seattle and Chicago with a stop in Spokane, Washington.
A local news director reported that passengers were "trapped" inside.
The incident occurred between the Havre and Shelby stops in Montana.