An entire town in North Dakota is being urged to evacuate after several cars of a train carrying crude oil derailed and blew up.
Explosions sent flames and thick black smoke billowing into the sky after a train carrying crude oil derailed near Casselton, North Dakota, about half an hour west of Fargo.
"We were taking a nap and then all of a sudden we heard this big boom and we ran outside and seen black smoke and orange smoke," says resident Brittney Koepplin.
As night fell Monday, local authorities warned a shift in the winds could push potentially toxic fumes from the blaze over the town of Casselton.
Police urged all 24-hundred residents to evacuate.
Resident Cora Koepplin says, "Just grabbed whatever and leave cause they were like outside my house waiting for us to leave."
Officials with B-N-S-F Railway Company believe a train transporting grain derailed and hit the train carrying crude oil, sparking the explosions and the fire.
A team from the national transportation safety board is on the way to help figure out what caused the accident.
Crews are letting the blaze burn itself out - so investigators aren't expected to get close enough to gather evidence until later today.
Health experts say breathing in the fumes from crude oil can cause red, itchy eyes and coughing. It can be especially problematic for people who already have problems breathing.