A BNSF crude oil train derailment in North Dakota early Wednesday involving 10 tanker cars remained under investigation Thursday.

The incident near Heimdal, ND, in Wells County, about 100 miles northeast of Bismarck, occurred around 7:30 a.m. CDT. The fire and smoke led local authorities to evacuate residents in the area. No one was injured, according to initial reports.

The train consisted of 109 total cars – 107 cars loaded with crude oil and two buffer cars loaded with sand, according to the state Department of Emergency Services.

At least two of the crude oil tank cars erupted into fire, according to Dave Glatt, head of the state Environmental Health unit. Glatt toldNGI's Shale Daily that reports from the scene indicated the fires were out by Wednesday afternoon.

State and federal inspectors are to determine by early Thursday if there was any contamination to nearby water supplies. A slough close to the accident feeds into the James River.

"Our people on the scene have reported that the smoke has gone down dramatically," said Glatt, noting that the smoke was potentially harmful to people because of its particulate matter, but it did not contain any toxic chemicals. Volatile organic compounds (VOC) are consumed in fires and don't pose a threat to local residents.

The latest incident is part of a string of crude train derailments over the last several years as multiple 100-car-plus trains roll daily from the Bakken oil field (see Shale Daily, Jan. 3, 2014). The latest occurred at about 7:30 a.m. CDT The incident comes less than a week after U.S. and Canadian authorities released final stringent rules for rail transport of flammable liquids, including crude oil (see Shale DailyMay 1). Those rules for new and retrofitted tank cars will be phased in through 2025.

Sarah Feinberg, acting administrator at the Federal Railroad Administration (FRA), said a 10- person investigation team has been deployed to the site.

The “incident is yet another reminder of why we issued a significant, comprehensive rule aimed at improving the safe transport of high hazard flammable liquids," Feinberg said. "The FRA will continue to look at all options available to us to improve safety and mitigate risks.”

The tank cars involved in the incident are the unjacketed CPC-1232 models, which would not meet the newest federal standards, a BNSF spokesman told NGI’s Shale Daily.

BNSF personnel also were at the scene of the incident.

The cause of the incident remained under investigation, the BNSF spokesman said, with “details regarding the operation of the train...only being shared with federal investigators at this time.”