NEW : Debate over whether it was human - caused -- intentional or unintentional . Deadly wildfire has charred over 140,000 acres in Northern California . Two firefighters killed ; fire 28 percent contained ; up from 22 on Wednesday . People fled from their homes since fire started last Wednesday .
NEW : Debate over whether it was human-caused -- intentional or unintentional . Deadly wildfire has charred over 140,000 acres in Southern California . Two firefighters killed ; fire 28 percent contained ; up from 22 percent Tuesday . Residents fled from 10,000 homes since fire started last Wednesday .