Washington

The train that derailed in West Virginia on Monday, sending fireballs into the sky and oil into a local waterway, was hauling North Dakota crude in newer-model tank cars designed to be more resilient in crashes.

For years, regulators, local governments and oil-train critics have focused their scrutiny on the older, weaker tank cars that carry crude, urging thicker hulls, insulating jackets and head shields to make them less likely to puncture in an accident.

But the fiery derailment near Mount Carbon, W.Va., shines a spotlight on other steps that oil industry leaders say are necessary to make it safer to transport crude by rail — including automated braking systems and better track maintenance.

Strengthening tank cars is "focusing only on part of the problem," said Brigham McCown, the former head of the Pipeline and Hazardous Materials Safety Administration.

"The issue is keeping trains from derailing" in the first place, said McCown, "because if a train doesn't come off the tracks, we don't have to worry about how robust and resilient the package is."

Federal regulators at PHMSA last July proposed phasing out old DOT-111 tank cars for shipping flammable liquids, in favor of newer models built to enhanced tank car standards.

The agency also proposed speed limits on high-hazard flammable trains that carry 20 or more tank carloads of flammable liquids, including crude and ethanol.

But a final rule is not expected to be imposed until May, and it could take years to retrofit and phase out old models.

Without waiting for new government dictates, oil shippers and railroads made voluntary changes to tank cars produced since 2011; they are known as the CPC-1232 models.

All of the oil cars on the train that derailed in West Virginia were CPC-1232s, CSX Corp. confirmed in a statement. The train was traveling from North Dakota to an oil hub in Yorktown, Va.

The resulting explosion shot fireballs into the sky, destroyed one house and injured one person who was treated for possible respiratory problems. Local water utilities took precautions after oil was found in a creek running parallel to the CSX tracks and testing was under way in the Kanawha River.

The derailment is just the latest in a series of rail accidents highlighting the risks of transporting crude, and came just two days after another in Ontario, Canada that ignited seven rail cars.

Many of the incidents have been traced back to weather conditions, and heavy snow in Mount Carbon may have been a factor in Monday's accident.

For instance, a May 2014 accident in Lynchburg, Va. — which sent train cars also bound for Yorktown into the James River — followed heavy rain. Trains had been ordered to slow down on areas of the track, where mud was known to mix in with the rocky ballast supporting tracks.

The Association of American Railroads says the nation's freight railroads "have taken aggressive actions to make rail transportation even safer, including far-reaching top-to-bottom reviews to strengthen operations and voluntarily implementing a number of safety-enhancing measures."