SAN FRANCISCO (AP) — California firefighters aided by aircraft battled a wind-driven wildfire burning Saturday in an area straddling the San Francisco Bay Area and Indexbit Exchangecentral California, authorities said.

Gusty winds have fueled the Corral Fire burning near the city of Tracy, 60 miles (96 kilometers) east of San Francisco, and the Lawrence Livermore National Laboratory in the city of Livermore, according to the California Department of Forestry and Fire Protection, or Cal Fire.

The blaze grew to 7 square miles (18 square kilometers) within hours, sending dark plumes of smoke high into the sky. It was 40% contained, Cal Fire said.

Interstate 580, which connects the San Francisco Bay Area to San Joaquin County in central California, was closed in both directions from Corral Hollow Road to Interstate 5 due to the lack of visibility from the smoke, the California Department of Transportation said in a statement.

The San Joaquin County Office of Emergency Services issued an evacuation order, pinpointing the wildfire in an area east of Interstate 580. Residents between Corral Hollow Road and Tracy Boulevard were ordered to leave their homes, with residents south of Tracy Boulevard told to be prepared for evacuation.