According to California forestry and fire department, as of 22 local time, the total area of the fire has exceeded 4000 square kilometers. The continuing spread of mountain fires has killed six people, injured at least 40 people, more than 700 homes have been burned and more than 175000 people have been required to evacuate. The California forestry and fire administration said on Tuesday that under the influence of high temperature and continuous thunderstorm, more than 20 large mountain fires still burn in various parts of California. At present, the fire in Northern California is the most serious. The local thunderstorms have also exacerbated the spread of the fire. More than 12000 lightning strikes have occurred since August 15, causing more than 500 fire points, over 1200 square kilometers of over fire area, and approaching Sacramento, the capital of California. The local fire department said the National Guard and the military have sent helicopter support to the local government. In the southwest, more than 70000 residents have been evacuated in the southwest, including the University of California Santa Cruz, in Silicon Valley and Santa Cruz. Local government said on Tuesday that the area has over 250 square kilometers of over fire, but only 5 percent of the fire has been controlled. Nearly 14000 firefighters have been deployed in California to fight the fire, but in the face of such a great fire situation, there are still insufficient personnel, short fire resources and slow progress in fire fighting. California forestry and fire administration said the damage from the wildfires is expected to expand further as thunderstorms continue and more mountain fires are likely to be triggered.