HIGHLAND, Calif. (KABC) — A brush fire fueled by hot temperatures and dry brush that has triggered sweeping evacuation orders and warnings exploded in size in the Highland area, growing to 17,459 acres.

The Line Fire started Thursday evening, but the flames really kicked up and quickly spread Saturday as winds shifted and lightning strikes hit the area. Communities in the area were ordered to evacuate and roads were shut down.

According to the Cal Fire website, at least three firefighters have been injured, but details on their conditions were not released.

No homes have been reported destroyed as of Sunday morning, but 8,733 structures were threatened in the area including residential homes, commercial buildings and other minor structures.

Containment was at 0%.

Gov. Gavin Newsom proclaimed a state of emergency in San Bernardino County for the fire, and announced new federal grant money to help fight the blaze. The emergency declaration allows the government to waive certain regulations, letting people impacted by the fire to gain quicker access to unemployment benefits, for example, or obtain records they lost such as marriage and birth certificates. It also waives certain regulations on hospitals and child care facilities.

The state has also obtained a Fire Management Assistance Grant from FEMA, Newsom said. The grant allows local agencies to apply for reimbursement of up to 75% of their firefighting costs.

Officials say the blaze was generating its own weather conditions, as pyrocumulus – also known as fire clouds – formed overhead. The National Weather Service says some 3,700 lightning strikes were recorded in the clouds – and more than 270 lightning strikes on the ground which had the potential to ignite new blazes.

Thunderstorms were creating down drafts which were pushing the blaze in unpredictable directions, according to Chris Prater with San Bernardino County Fire.

“Firefighters are fighting a very tough battle,” Prater said. “They’re fighting in 100-plus degree temperatures. Very steep terrain. And some new weather conditions today with thunderstorms that came in.”

Authorities issued evacuation orders and warnings that remained in place Sunday. Multiple road closures are also in place.

Evacuation orders

• The area from Calle Del Rio to Highway 38, including north of Greensport Road.

• All undeveloped land east of Highway 330 to Summertrail Place and north of Highland Avenue.

• Areas of Running Spring east of Highway 330 and south of Highway 18

• The communities of Running Springs and Arrow Bear Lake

• The area east of Orchard Road to Cloverhill from Highland Avenue north to the foothills

• North of Highland Avenue and East of Palm Avenue to Highway 330

Evacuation warnings

• Neighborhoods east of Church St, north of Highland Ave

• Neighborhoods east of Weaver, north of Greenspot to the Iron Bridge

• Cedar Glen, Lake Arrowhead, Crestline and Valley of Enchantment

• Angelus Oaks, Seven Oaks, Mountain Home Village

Road closures

• Highway 18 is closed from Kuffel Canyon to the Big Bear Dam. Only outbound traffic allowed from Running Springs.

• Highway 330 remains closed from Highland Avenue to Highway 18 in Running Springs.

• Highway 18 is closed going northbound (inbound) from Kuffel Canyon to Running Springs. Only southbound (outbound) traffic is allowed.

• Highway 18 is closed from Running Springs to Highway 38 (Big Bear Dam).

• Highway 330 is closed from Highland Ave to Highway 18 in Running Springs.

Evacuation shelters

• Immanuel Baptist Church located at 28355 Base Line Street

• San Bernardino County Fairgrounds, Building 6 located at 14800 7th Street

• Animals can be taken to Devore Animal Shelter located at 19777 Shelter Way

Meanwhile, the cause of the fire is under investigation.