Oil cars from a derailed train in West Virginia were still smoldering on Tuesday as investigators tried to figure out what happened in the first place.

According to Edward McAllister of Reuters, CSX Corp., the train operator, said that it was hauling North Dakota crude on newer model tank cars. A report from Fox News noted that the train company confirmed that the cars in question were CPC 1232 models.

"There's nothing there," Sen. Joe Manchin, D-W. Va., said as he toured the accident scene. "All you can see is a couple of blocks sticking out of the ground. There's some pickup trucks out front completely burned to the ground."

According to McAllister, CSX said in a statement that the fires, which destroyed one house and required the evacuation of two towns, were left to burn out. No other serious injuries were reported.

"The derailment resulted in the evacuation of hundreds of families as 19 cars slammed into each other and caught fire, leaking oil into a Kanawha River tributary and burning down a nearby house," Fox News wrote. "The area lost its drinking water and electricity, and fire crews said Tuesday they had little choice but to let the cars burn themselves out."

Fox News added that each car on that train carried up to 30,000 gallons of crude.

McAllister reported that the CPC 1232 was supposed to be a newer, tougher version of the DOT-111 car manufactured before 2011. Fox News noted that according to the Railway Supply Institute, an estimated $7 billion has been spent to put 57,000 of the new cars into service.

"The Obama Administration is considering requiring even more upgrades, such as thicker tanks, shields to prevent tanks from crumpling, rollover protections and electronic brakes that could make cars stop simultaneously, rather than slam into each other," Fox News wrote. "Some of the measures would cost billions more and have been strongly opposed by the oil and rail industries."

In the meantime, CSX regional vice president Randy Cheetham told Fox News that no cause has been determined yet. He contended that the tracks were inspected just three days before the train wreck.

"They'll look at train handling, look at the track, look at the cars," Cheetham said. "But until they get in there and do their investigation, it's unwise to do any type of speculation."

The National Transportation Safety Board will attempt to compare this incident with other wrecks, according to Fox News.

"This accident is another reminder of the need to improve the safety of transporting hazardous materials by rail," NTSB acting chair Christopher Hart said.

Fox News reported that West Virginia is one state where train operators can transport hazardous materials like crude oil in secrecy. However, while CSX and other railroad companies have claimed the information is proprietary, a federal order requires them to tell state emergency officials where trains carrying crude oil are traveling.