(Reuters) - Two people were killed fighting lightning-sparked California wildfires, and tens of thousands have evacuated homes as the state scrambles to find more firefighters.

The deaths on Wednesday of a utility worker and helicopter pilot participating in the fire response came after nearly 11,000 lightning strikes hit the state over a 72-hour stretch this week, igniting 367 fires. Authorities are warning all 40 million state residents to be ready to evacuate, if necessary.

At least nine fires raced through hills and mountains adjacent to Northern California's drought-parched wine country about 35 miles (56 km) southwest of Sacramento.

With several joining up, they formed a 131,000 acre (53,000-hectare) "megafire" nearly 10 times larger than New York's Manhattan island across five counties.

Collectively known as the LNU Complex Fire, the fires destroyed at least 105 structures in the Vacaville-Fairfield area. A PG&E utility worker died helping first responders and at least four civilians were injured, according to a California Department of Forestry and Fire Protection (CalFire) spokeswoman.

"It was the scariest thing I've ever seen, the heat, and it came so fast," Stacy Kline, a Fairfield resident whose rural home was saved by her husband, friends and firefighters, told local television station ABC7 News.

In central California a helicopter was on a water-dropping mission in Fresno County about 160 miles (260 km) south of San Francisco when it crashed, killing pilot Mike Fournier, 52, a contractor who was a former TV news helicopter pilot and high school football coach, his family said.

Another cluster of lightning-strike fires burned across 40,000 acres of San Mateo and Santa Cruz counties around 13 miles south of Palo Alto, injuring three first responders, forcing 22,000 to evacuate and destroying 20 structures, CalFire said.

Fanned by "red-flag" high winds, the fires are racing through vegetation parched by a record-breaking heat wave.

California Governor Gavin Newsom requested 375 fire crews from out of state as resources ran thin.

 

(Reporting by Steven Lam; Additional reporting by Andrew Hay; Editing by Frances Kerry and Cynthia Osterman)