It started with a small, illegal campfire. Now an area the size of San Francisco has been scorched in a deadly blaze ripping through California's Monterey County since July 22. State fire officials announced the cause of the blaze, dubbed the Soberanes Fire, in a closed area of Garrapata State Park near the Big Sur coast on Tuesday, though they still aren't sure who started it, report Reuters and KPCC. A man helping to fight the larger blaze died when his bulldozer rolled over on July 26. The blaze has also destroyed 57 homes, destroyed or damaged 15 other buildings, and led to hundreds of evacuations in a 67-square-mile area, reports the Los Angeles Times. It was 25% contained as of Tuesday.
Some 5,500 firefighters have only been able to draw containment lines around 18% of the fire as they battle "pretty extreme, steep terrain," shifting winds, and an "unusually active" fire at night, says a Cal Fire rep. "Most fires, we get a little bit of moisture recovery and humidity at night, but, unfortunately, that has not been the case on this entire fire so far, so we haven’t had that slower fire growth," he says. Humidity levels at night have been "incredibly low" at about 5%. A separate 2,185-acre fire sparked Saturday has also destroyed five structures, including three homes, in Fresno County and is threatening 400 other structures, officials say. That fire was at least 30% contained on Tuesday. (Read more California wildfires stories.)