SANTA CRUZ, Calif. • More than two dozen major fires were scorching California on Thursday and taxing the state’s firefighting capacity, sparked by an unprecedented lightning siege that dropped nearly 11,000 strikes over several days.

The fires have destroyed 175 structures, including homes, and are threatening 50,000 more, said Daniel Berlant, an assistant deputy director with the state Department of Forestry and Fire Protection.

In all, 33 civilians and firefighters have been injured, and two people have died.

Most of the activity is in Northern California, where fires have chewed through about 500 square miles of brushland, rural areas, canyon country and dense forest surrounding San Francisco.

More than 10,000 firefighters are on the front lines, but fire officials in charge of each of the major fire complexes say they are strapped for resources. Some firefighters were working 72-hour shifts instead of the usual 24 hours. The state has requested 375 engines and crew from other states.

“That’s going to allow our firefighters that have have been on the front line since this weekend to have an opportunity to take some rest,” Berlant said.

In Marin County, just north of San Francisco, where a smaller fire is burning near the Pacific Ocean, county fire chief Jason Weber said he is waiting for assistance from Montana to arrive this weekend.

He said in his 25 years in fire service, “we’ve never seen this level of draw-down” from cooperating agencies, as there is heavy competition in the western United States for equipment and people.

In the coastal mountain regions south of San Francisco, where 26,000 people were under orders to evacuate, the CZU complex fire grew overnight to 62 square miles.

Officials warned it has the potential to grow significantly in the next day. Given depleted resources, one of the best tools firefighters have for public safety is to get people out of harm’s way. But some people refused when officers went door to door Wednesday night, Cal Fire Chief Mark Brunton said.

“With the resources that we are lacking, we ask you to help us to help us to do our jobs and to keep the public safe,” he said.

Two fires in Sonoma County prompted evacuation orders for 8,000 residents near the Russian River on Wednesday.

Flames from the LNU Lightning Complex fires burn in Napa County, Calif., on Tuesday. The blaze went on to destroy multiple homes near Lake Berryessa. Fire crews across the region scrambled to contain dozens of wildfires sparked by lightning strikes as a statewide heat wave continues.

the associated press