CNN affiliate KGO reported that people as far as a half-mile away said they felt the boom and heat of the explosion . NEW : An evacuation plan has been set up . Hospital officials say patients have arrived with minor injuries . The fire is about 20 miles from San Francisco International Airport . Helicopters are dropping bombs on houses to stop its spread .
NEW : An evacuation plan has been set up . Hospital officials say patients have arrived with minor injuries . The fire is about 20 miles from San Francisco International Airport . Helicopters are dropping bombs on houses to stop its spread .