BAILEY, Colo.?A 2,400-acre wildfire sent thick smoke across wooded foothills southwest of Denver on Thursday as fire fighters labored in cooler weather to protect hundreds of homes.

Cloud cover, lighter winds and lower temperatures provided relief for about 250 fire fighters building lines around the blaze.

The Colorado fire broke out Tuesday in tinder-dry ponderosa, grass and brush. Whipped by winds, it spread quickly and doubled in size Wednesday night.

The entire town of 4,400 people was evacuated Wednesday afternoon, and four schools were closed when flames crept to within a quarter-mile of downtown. Three schools remained closed Thursday. The fire started in an area popular with smokers. No arrests have been made.

Foresters said the blaze was the top-priority wildfire in the nation as winter drought has triggered an early start to the wildfire season.