BISMARCK, N.D. — Residents of the southeastern North Dakota town of Casselton are welcoming a return to normalcy after an oil train derailment and fire while railway crews spent New Year’s Day working in subzero weather to get the track ready to reopen Thursday.

Mayor Ed McConnell was back at his trucking business Wednesday, finishing year-end work he said he typically completes the day before the holiday.

“It’s like taking a day and a half out of your life,” he said of the disruption caused by Monday’s derailment of a mile-long BNSF Railway train carrying explosive crude oil. No one was hurt, but the wreck and resulting blaze about a mile from the town of 2,400 people prompted the voluntary evacuation of most residents due to potentially unsafe air.

The town’s voluntary evacuation recommendation was lifted Tuesday afternoon after air quality tests, and a Red Cross shelter set up at the high school was shut down.

Renee Steen, who lives with her family about half a mile from the crash site, stayed temporarily with a friend in Fargo, about 25 miles to the east. She was back in her home Wednesday, watching through her window as crews worked at the crash scene. There was no smoke damage inside her home, she said.

“We noticed a lot of soot in the snow in our yard, and we are going to be changing out our furnace filter as a precaution,” she said.

The National Transportation Safety Board is investigating the crash and planned an update briefing late Wednesday in Fargo. The agency said earlier that a westbound BNSF train carrying grain derailed first, and a portion of it fell onto an adjacent track carrying the eastbound BNSF oil train. Eighteen cars on the 106-car oil train derailed and burned.

Earlier, McConnell called for federal lawmakers to address safety concerns posed by transporting oil by rail.

“There have been numerous derailments in this area,” he told The Associated Press. “It’s almost gotten to the point that it looks like not if we’re going to have an accident, it’s when.”

While the rate of oil train accidents remains low, there has been a sharp increase in the past several years in the number resulting in accidental releases. That increase is being driven by a surge in drilling in North Dakota and other western states.

There were no visible flames from the train wreckage Wednesday, said Cass County Deputy Greg Smith, who was working traffic control in the area.

“It appears to be just smoldering right now,” he said.

The temperature Wednesday morning in the area was 15 degrees below zero, with a wind chill factor about twice that cold, Smith said.

“Not the greatest conditions we could be asking for,” he said.

Railroad spokeswoman Amy McBeth said crews are used to the cold weather and know how to deal with it.

“We’ve operated in North Dakota for over 100 years,” she said. “You learn to operate in extreme weather here and in other places. The crews prepare for that.”

The railroad expected to reopen both lines in the area about midnight, McBeth said. Rail traffic in the meantime was being rerouted on other lines. McBeth said there might be some train delays but she was not aware of any major backups.

The railroad planned to open a claims center at 8 a.m. Thursday at the Days Inn Casselton for residents with evacuation-related expenses or with interrupted businesses due to the derailment.

Follow Blake Nicholson on Twitter at http://www.twitter.com/NicholsonBlake