MOUNT CARBON, W.Va. — Fires burned for nearly nine hours after a train carrying more than 100 tankers of crude oil derailed in a snowstorm in West Virginia, plunging at least one tanker into a river while sending a fireball into the sky, authorities and residents said.

Officials evacuated hundreds of families and shut down two water treatment plants threatened by oil seeping into the river following the Monday afternoon derailment. A state public safety division spokesman, Lawrence Messina, said fire crews decided to let the tanks burn themselves out.

Federal railroad and hazardous materials officials are probing the accident, in which part of the train formation hit a house. The office of Gov. Earl Ray Tomblin, which has issued a state of emergency, said the tanker cars were loaded with Bakken crude from North Dakota and headed to Yorktown, Va.

All but two of the 109 cars being hauled were tanker cars, officials said. One person was treated for potential inhalation issues, but no other injuries were reported, according to a statement from CSX, the train company.

WASHINGTON — The season's first major snow storm to blast large parts of the South struck early today at the nation's capital, poised to head up the winter-weary East Coast.After weeks of snow in the Northeast, the mid-February storm raked several Southern states Monday, when many schools and business were closed for Presidents Day. By this morning, it was moving into the Mid-Atlantic states, prompting the federal government to close Washington-area offices to most workers, keeping tens of thousands of commuters off the roads and rails today.A winter storm warning remained in effect for the Washington area until noon today with the National Weather Service predicting 6 to 8 inches of snow.