Fire-fighters took advantage of a drop in the winds Tuesday and attacked a resurgent wildfire that forced evacuation of 500 people.

About 50 fire trucks were stationed around the 50 evacuated homes to prevent the flames from striking them. However, the winds that kicked up Monday night and sent the blaze over a firebreak subsided to about 20 mph, easing fears the homes would be leveled.The sudden high winds that gusted to 55 mph prompted officials to order a voluntary evacuation of about 500 people from rural homes along Pleasant Valley Road. More than 60 people were evacuated Saturday night, just after the fire broke out.

Firefighters previously found an incendiary device they believe started the fire, which has charred 18,000 acres of brush and trees, and sent smoke and soot drifting as far as San Francisco 50 miles away.

"The winds started gusting late this afternoon and caused havoc," said Jim Shea, spokesman for the California Department of Forestry. "We're calling in more firefighters."

Another 600 firefighters were rushed into the battle Monday night, boosting the force to about 1,250 as the blaze spread another 300 acres. None of the evacuated homes was reported damaged.

As they had the night before, winds diminished after sundown to about 20 mph, aiding firefighters' effort to ring the fire.

Containment, originally predicted for Tuesday, was pushed back 36 hours to 6 p.m. Wednesday. The blaze was about half surrounded by late Monday night.

The fire destroyed seven ranch houses, 10 other structures and several radio transmission towers worth $7 million. More than 550 people were evacuated.

About 200 miles to the north, near scenic Lake Shasta, more than 1,300 firefighters struggled to contain a 7,800-acre grass and timber blaze that grew by another 1,500 acres on Monday.

A survey, a state spokesman said, showed 13 homes and 11 mobile homes were ruined by the flames. Containment was predicted for Wednesday night with full control the next day.

Two workers were critically injured when a burning tree fell on them as they tried to restore a power line.