A three-alarm fire raced through part of a construction site in the Woodlawn section of Fairfax County yesterday morning, leveling two apartment buildings and a clubhouse and causing more than $1 million in damage, according to Fairfax County fire officials.

Authorities had established no cause for the blaze by late yesterday.

Officials said the fire was reported at 11:05 a.m. at the Oaks of Woodlawn apartment complex at 8799 Old Mill Rd.

The fire spread quickly through the three-story, wood-framed apartment buildings and then spread to the clubhouse, officials said.

Nine firefighters were treated and released at Mount Vernon Hospital for heat exhaustion, minor burns and bruises, officials said. No civilians were injured in the fire, they said.

More than 50 firefighters from seven county fire stations and Alexandria responded to the blaze, officials said.

They said it was under control by 11:47 a.m., although firefighters were hosing down minor fires until about 12:20 p.m.

Officials said embers from the fire sent aloft by strong winds crossed to the east side of Rte. 1 and ignited brush fires as far as 1,000 yards from the construction site.

The buildings, scheduled to be open for renters in the late summer, were a little more than half complete, according to a spokesman for Amurcon Corp. of Virginia, the Richmond-based construction firm that is principal owner of the development.

The two razed apartment buildings contained 24 units each. Seven apartment buildings were planned for the eight-acre site.