More than two dozen major fires blazed through California on Thursday, as tens of thousands were forced to flee to safety. 

At least six people have died in the fires, the California Department of Forestry and Fire Protection (CalFire) reported Thursday night. A pilot was killed, after a firefighting helicopter crashed in Fresno County near San Francisco, on Wednesday. A utility worker died in Vacaville while trying to help first responders.

Lightning struck the state around 11,000 times, igniting about 370 fires  in Northern California. The fires doubled in size over 24 hours, exacerbated by the heatwave that the state is currently experiencing.

More than 10,000 firefighters have been working to tackle the calamity. But authorities say that are at the limit of their resources when it comes to manpower and equipment. Some 375 crews have been requested from other states.

"That's going to allow our firefighters that have have been on the front line since this weekend have an opportunity to take some rest," said Daniel Berlant, assistant deputy director with the state Department of Forestry and Fire Protection (Cal Fire). Some firefighters have been working for almost 72 hours, as opposed to their usual 24-hour shifts. 

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California governor Gavin Newsom thanked those on the frontline, who were working to protect civilians from the fire.

More than 175 structures have been destroyed, and 50,000 more are at risk. About 33 civilians and firefighters have been injured so far. 

The fires, collectively known as the LNU complex, sent wind-driven flames at 120 feet a minute across grassland parched by record-breaking heat, according to the fire department. 

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Governor Newsom requested reinforcements since prisoners usually conscripted for firefighting were either subject to a lockdown due to COVID-19, or had been released from prison to slow down the spread of the virus. 

The air quality in San Francisco area reached dangerous levels, and evacuation orders have been issued. The fires have also affected Santa Cruz County, and caused severe damage to California's oldest state park, Big Basin Redwoods State Park. 

tg, kmm/ng (AFP, AP, Reuters)