SIMI VALLEY, Calif. (AP) — Thousands of people were ordered to evacuate Monday as a wind-driven wildfire threatened suburban homes in Southern California.

The Sandy Fire was reported around 10 a.m. in hills above Simi Valley, about 30 miles (48 kilometers) northwest of Los Angeles.

By mid-afternoon it had consumed more than 500 acres (200 hectares) of dry brush and damaged at least one home, according to the Ventura County Fire Department.

The flames were pushed by morning gusts that topped 30 mph (48 kph) but were subsiding later in the day, said according to fire department spokesperson Scott Dettorre.

“As the sun sets, those winds will calm down even more,” Dettorre said.

Evacuation orders and warnings were issued for several neighborhoods in Simi Valley, a city of more than 125,000 people that was shrouded in smoke as helicopters performed water drops. Dettorre didn’t know exactly how many people were ordered to leave.

The Ronald Reagan Presidential Library and Museum, perched on a hillside a few miles away, said it was closed for the day because of the fire.

The cause is under investigation.

Meanwhile, firefighters were battling a 15-square-mile (39-square-km) blaze on Santa Rosa Island, the second-largest of the Channel Islands off the Southern California coast. The fire destroyed a cabin and an equipment shed and forced the evacuation of 11 National Park Service employees.

Santa Rosa, a popular destination for camping and hiking, is home to island foxes, spotted skunks and elephant seals.