More than 17,000 people were under evacuation orders in Southern California on Tuesday as a fast-moving wildfire threatened suburban neighborhoods in Simi Valley, a Ventura County city northwest of Los Angeles. The Sandy Fire was reported Monday just after 10 a.m., and fire officials said the blaze had grown to more than 180 acres by Tuesday morning.

Fire activity was shaped by the local weather. Officials said the flames were initially pushed by gusts that topped 30 mph, but calmer winds overnight helped crews continue their work into Tuesday. Ventura County Fire Department spokesperson Andrew Dowd said crews had made progress against the fire with the improved conditions and that they were hoping to make further gains before winds increased again.

As aircraft made water drops, evacuation orders and warnings remained in place for several neighborhoods in Simi Valley. The city, which is home to more than 125,000 people, was shrouded in smoke during the latest firefighting operations.

By Tuesday morning, the Ventura County Fire Department reported the Sandy Fire was 5% contained. Officials said the cause of the fire was under investigation.

The fire was also destroying structures in its path. Ventura County officials said the blaze had consumed more than two square miles of dry brush and destroyed at least one home by Tuesday morning.

Fire crews were also responding to a separate wildfire on Santa Rosa Island, off the Southern California coast. Officials said that blaze covered 23 square miles, destroyed a cabin and an equipment shed, and forced the evacuation of 11 National Park Service employees, with no containment reported as of Tuesday morning. Santa Rosa Island is a popular destination for camping and hiking and is home to island foxes, spotted skunks and elephant seals.