The siege or burning of Washington was an attack during the war of 1812 by British forces and those of the United States of America. The American troops had been defeated by at the Battle of Bladensburg by troops led by Major General Robert Ross. His forces later went on to occupy then Washington City and destroy a number of buildings, including the White House.
To quote the Architect of the Capitol (yes, you or your unborn children pay for that, too) recently:
"The British focused their destructive work on the principal rooms, foregoing the lobbies, halls and staircases, thus securing their escape route. In the south wing, soldiers ignited a giant bonfire of furniture slathered with gunpowder paste in the Hall of the House of Representatives. The heat from the fire grew so intense that it melted the glass skylights and destroyed much of the carved stone in the room, including Guiseppe Franzoni's life-size marble statue of Liberty seated on a pedestal, located above the Speaker's rostrum.