At least 600 firefighters are struggling to control the wildfire. So far, the fire has damaged between 300 and 400 homes, according to the state fire marshal's office. Chris Judson of the U.S. National Park Service told CNN that Thursday's stronger winds had strengthened the fire, as it spread quickly from 3,700 acres on Wednesday to engulfing about 18,000 acres by Thursday morning. At least 600 firefighters were struggling to control the blaze, set a week ago to clear brush at a nearby national park. The fire flared out of control and raced through stands of ponderosa pine.
Lower humidity can dry brush even more, making it more flammable.
Lab closed as precaution The laboratory declared a general emergency at 11 p.m. Wednesday, saying there were grass and brush fires at three of its research facilities. Its weapons-engineering tritium facility at Technical Area 16 was swept by fire, but the masonry building was left intact, lab officials said. The facility was closed as a precaution earlier this week, but critical operations are still being maintained. Officials said explosives and radioactive materials were in fireproof storage areas. Just after sundown, flames spread to a ridge overlooking downtown, lighting the night sky.