A fire resulting from a gas line leak yesterday in McLean sent three men to the hospital with minor burns and forced a temporary evacuation and disruption of gas service for 26 families in a three-block area.

Workers repairing a water line about 2:30 p.m. near 1010 Shipman La. south of Georgetown Pike struck the four-inch steel gas main, causing a leak "large enough for a sufficient amount of gas to escape," said Paul Young, a Washington Gas Light Co. spokesman.

The leak, which occurred in a ravine about a hundred feet from the nearest house, was reported to Fairfax County fire officials, who called the gas company, Young said.

A gas company crew arrived and was preparing to clear a hole around the leaking line when the gas ignited, Young said. Fire officials, who were already present, said they quickly contained the small ensuing brush fire.

Young called the ignition "a little puzzling" and "unusual." Thus far, he said, it appears that the ignition was caused by sparks from the small digging apparatus that the gas company was using to dig the hole around the line. The extremely dry conditions, he said, also may have been a contributing factor.

Washington Gas foreman Rase Jones, 51, and crew mechanic Joel Gibson, 29, along with Wade Stanley, 35, an employe of E.C. Ford, a gas company subcontractor, were taken to Fairfax Hospital. Jones and Stanley were admitted with second degree burns and are listed in good condition. Gibson was treated and released.