(Updates with clean-up to take several days; evacuation numbers; water testing; color from scene)
By Kara Van Pelt
BECKLEY, W.Va., Feb 16 (Reuters) - A CSX Corp train hauling North Dakota crude derailed in West Virginia on Monday, setting a number of cars ablaze, destroying a house and forcing the evacuation of two towns in the second significant oil-train incident in three days.
One or two of the cars plunged into the Kanawha River, said Robert Jelacic of the West Virginia Department of Homeland Security and Emergency Management.
CSX said the train was hauling 109 cars from North Dakota to the coastal town of Yorktown, Virginia, where midstream firm Plains All American Pipelines runs an oil depot. It said one person was being treated for potential inhalation of fumes. No other injuries or deaths were reported.
As of 9:30 p.m. local time, billowing flames could still be seen coming from several rail cars and something appeared to be burning on the partially frozen river.
Clean-up was expected to take several days, as the fires burn themselves out, said Joe Crist, Fayette County fire coordinator. About 200 residents were evacuated.
Crist said West Virginia American Water was testing to see if Kanawha River water had become contaminated.
West Virginia State Police First Sergeant Greg Duckworth, who was at the crash site, said that nine or 10 of the cars had exploded at intervals of about every half hour. A similar sequence has occurred in a handful of other derailments over the past year and a half, with the fire from one tank heating up gases in the next nearest car, causing it to ignite.
"It's a real mess down here," Duckworth said.
Crist said freezing temperatures and constant snowfall is making clean-up difficult.
A mile-wide area around the incident was evacuated after a house caught fire, said Lawrence Messina, spokesman for the West Virginia Department of Military Affairs and Public Safety.
West Virginia Governor Earl Ray Tomblin declared a state of emergency for Kanawha and Fayette counties.
The train derailed at 1:20 p.m. EST about 33 miles (54 km) southeast of Charleston, the state capital, according to Fayette County 911 Coordinator James Bennett.
The derailment occurred less than 200 miles (320 km) west of Lynchburg, Virginia, where another CSX train also bound for the Plains terminal in Yorktown derailed and erupted last April. Plains did not immediately return calls seeking comment.
The latest incident came just two days after a Canadian National Railways train from Alberta's oil sands derailed in a wooded area of northern Ontario. CN said 29 of 100 cars were involved and seven caught fire. No injuries were reported, but the cars were still on fire on Monday.
A boom in oil shipments by rail and a spate of derailments across North America have put heightened focus on rail safety. In 2013, 47 people were killed in the Quebec town of Lac-Mégantic after a train carrying crude oil derailed and exploded.
The latest incidents will likely refocus attention on U.S. and Canadian regulators' efforts to improve the safety of such shipments, which have spurred concerns over both the flammability of very light oil from the North Dakota Bakken shale as well as the flawed design of older tank cars.
The U.S. Transportation Department has submitted a proposal to the White House to require adding an extra 1/8th inch of steel to most existing oil train tank shells, while new models would have the thicker hull installed on the factory floor.
It was unclear what kind of tank cars were involved in the derailment on Monday. (Reporting by Kara Van Pelt in Beckley, W.Va., Marcus Constantino in Boomer, W.Va., and Jonathan Leff in New York; Editing by Chris Reese, Tom Brown, Mary Wisniewski, Peter Cooney and Eric Walsh)