Officials on Monday night were calling for the evacuation of the entire town of Casselton, N.D., after a BNSF grain train derailed and crashed into a crude oil train in North Dakota on Monday afternoon, causing tank cars to explode in towering mushroom-cloud flames.

No one was injured in the accident that happened about 2:10 p.m. near Casselton, about 20 miles west of Fargo, but smoke billowed for hours.

Monday night, however, the Cass County Sheriff's Office was "strongly recommending" that the town's 2,300 residents leave immediately. Those who live within 5 miles south and east of the city also were told to leave.

"Information from the National Weather Service indicates a shift in the weather resulting in a high pressure system that will push the plume of smoke down increasing the risk of potential health hazards," the sheriff's office said in a news release.

Amy McBeth, a spokeswoman for BNSF, said a grain train derailed on a track parallel to an eastbound crude oil train with 106 tank cars, striking some of the tanks and triggering explosions.

It was not clear how many tank cars were struck, nor how many were burning, she said.

"It was black smoke and then there were probably four explosions in the next hour to hour and a half," said Eva Fercho, a Casselton resident who saw the fiery aftermath.

An estimated 11 to 12 crude oil unit trains depart daily from the oil region in western North Dakota. Lacking sufficient pipelines, 69 percent of the state's oil is currently shipped to market by rail. The main railroads, BNSF and Canadian Pacific, have tracks through the Twin Cities.

Fercho said the BNSF main line runs right through Casselton, and just two blocks from her home.

"We are very thankful it didn't happen in the city limits," she said.

The accident also spared the Tharaldson Ethanol plant, west of Casselton. Plant Manager Ryan Carter said the accident was about 2 miles away from the plant, but the burning tank cars were visible from there.

"It was pretty much flames and smoke," said Carter, who estimated that about 30 tank cars were involved.

Carter Hackmann, who lives about a mile away from the site of the wreck, said he heard at least three explosions, and took photographs from his house of billowing flames and smoke that resembled a mushroom cloud.

The city sent out e-mail alerts warning people to stay indoors.

North Dakota officials have said that even more crude oil is expected to move by rail in 2014. The state is approaching 1 million barrels per day in output, and trails only Texas and the separately counted Gulf of Mexico in U.S. oil production.

In July, a runaway train loaded with North Dakota crude oil crashed in Lac-Mégantic, Quebec, killing 47 people and destroying that city's downtown as tank cars exploded and burned.

David Shaffer • 612-673-7090 • @ShafferStrib