The San Bernardino County Sheriff's Department said surrounding populated areas in Baldwin Lake, Holcomb Valley and around the Big Bear dump were being evacuated. Officials haven't released what was being stored in the buildings.
The blaze, which broke out at around 3 p.m. Monday, was 10 percent contained as of 7:25 a.m. Tuesday, according to InciWeb.
Voluntary evacuation orders were issued as firefighters battled an estimated 850-acre brush fire in Big Bear Monday afternoon.
"Residents are fine - not too anxious", VanOostendorp said by phone Tuesday morning. But firefighters said a sudden boom in the fire has prompted mandatory evacuations for homes located on the northeast portion of Holcomb Valley Road and Highway 18.
A wildfire in the San Bernardino Mountains continued to grow overnight as warm temperatures and low humidity helped push flames over a ridge top and deeper into rugged terrain, authorities said Tuesday.
Closures remain, with Highway 18 closed between Delta Avenue north to Mitsubishi Plant Road.
Hikers should avoid Pacific Crest Trail at Highway 18 to Van Dusen Road and Doble Trail and Tanglewood Group Campgrounds are also closed. One firefighter had suffered a heat-related injury, officials told CBS2.
The cause of the fire was unknown. Other resources included 18 engines, 16 hand crews, six helicopters and eight air tankers including a massive DC-10 that can carry 12,000 gallons of water or fire retardant.
An information line has been set up for the fire at 909-383-5688.