A historic mansion just across Occoquan Gorge from Fairfax County was destroyed last night by a fire that burned out of control well into this morning.

"I think it's washed up," Lt. Roger Cordani of the Prince William County fire department said of Rockledge, the 11-room, three-story structure designed in 1758 by famed colonial architect William Buckland.

"The second floor was gone when [firefighters] got there," Cordani said. The blaze "was burning through the roof."

About 60 or 70 persons worked into the early hours of this morning in an effort to control the blaze, which was reported about 11 p.m.

Shortly after midnight, firefighters reported the blaze under control, "but it got away from them again," Cordani said. The only thing left of the historic pre-Revoluntionary mansion "was the stone frame," he said.

The splended gray stone mansion in Prince William County was once described in a federal survey of historic buildings as being "worthy of most careful preservation for the benefit of future generations."

The cause of the fire could not be immediately learned.

Rockledge architect Buckland also designed the famed George Mason's Gunston Hall in Fairfax County and the Hammond Harwood House in Annapolis.

Two woman firefighters were reported injured in the blaze.