The entire town of Lac-Megantic in Quebec, Canada, was evacuated after a freight train carrying crude oil derailed and caught fire, officials told ABC News.
The 80-car-long freight train exploded at approximately 1 a.m. Saturday morning, filling the sky with thick, black smoke.
Authorities said at least 30 buildings were destroyed.
Several people are reported missing.
Sgt. Gregory Gomez del Prado, a spokesman for Quebec Provincial Police, said officials "fear that there are going to be fatalities."
Gomez del Prado said there are also several hazards they're dealing with.
"There's the smoke that could cause a hazard to the people in the area, of course the water will also be a problem because of the fact that there was some crude oil and the fact that the crude oil has been leaking in the environment and the lake nearby," Gomez del Prado said.
Lac-Megantic Resident Anne-Julie Hallee witnessed the explosion.
"This sky was red, yellow. It was like, it was like the end of the world," she said.
Lac-Megantic is located about 155 miles east of Montreal.
Dispatcher Stan Wheeler with the Franklin County Sheriff's Office in Maine told ABC News Radio that more than 30 firefighters responded to the massive fire.
Radio-Canada reported the train was en route to Maine. It is unclear how the train derailed, or if there are any victims at this time.
"Thoughts & prayers are with those impacted in Lac Megantic. Horrible news," tweeted Canadian Prime Minister Stephen Harper.
ABC News Radio contributed to this report.