WATCH: Oakland Hills Grizzly Peak Fire Spreads, Threatens UC Berkeley Campus

A rapidly spreading fire in the Oakland Hills near Grizzly Peak Boulevard and Fish Ranch Road in Alameda County, California, has more than 150 firefighters from nine departments, who are still battling the brush fire that started Wednesday afternoon and was said to have grown to 20 acres.

Crews are expected to be at the scene throughout Wednesday night and into Thursday.

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Fire officials assisting at the scene said a California fire crew member was injured Wednesday evening when he was battling the five-alarm fire near the Berkeley-Oakland border.

According to California Fire Battalion Chief Mike Marcucci, a group of inmate firefighters were on a hillside battling the fire when they hit a bee hive by mistake. As they struggled to get away from it, one of the inmate firefighters lost control and fell 50 feet down a hillside. He suffered head and facial injuries and was immediately taken to a nearby hospital and is expected to survive, according to Marcucci, San Francisco CBS Local reported.

The officials at the University of California, Berkeley (U.C. Berkeley), issued a fire alert shortly after 2:30 p.m. EDT, and asked Pacific Gas and Electric Company (PG&E) to shut down the school's transformers immediately. The officials also advised people inside the campus to not use the elevators until the power was back. However, the power was still on as of 4:15 p.m. EDT after PG&E inspected the power lines and issued a statement saying no campus outage was required.

"CAL FIRE requested that PG&E prepare to de-energize two transmission lines near the area of the fire burning in the Oakland Hills for firefighter safety. We notified UC Berkeley that we may need to de-energize the lines, which interconnect into the campus’s power grid. UC Berkeley has its own internal power system. Due to changing conditions of the fire, CAL FIRE did not ask us to de-energize the two transmission lines. We are standing by to support CAL FIRE and our customers as needed," PG&E said in a statement, according to ABC7 News.

The burning vegetation fire, which was first reported around 1p.m. EDT and was approximately burning a mile from the Berkeley border and heading East, was said to have spread 20 acres as of 5:15 p.m. EDT and was 20 percent contained, according to a tweet on Alameda County Fire Department's account.

However, the biggest challenge faced in containing the fire was the hilly terrain and heavy vegetation in the area.

"At this time forward progress on the fire has been stopped. What we have now is a very difficult mop-up and final extinguish operation, primarily due to the heavy vegetation on the Grizzly Peak, on the Contra Costa County side," Moraga-Orinda Fire District Chief Stephen Healy said, ABC7 News reported.

Traffic has been stopped in the area and residents were asked to stay off the Grizzly Park Boulevard. "Anyone who lives in the hills and is preparing to go home should expect delays," the Berkeley Police Department said, according to Berkeleyside.com.

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Fire officials said the fire was still spreading at a moderate rate. Orinda Police provided a shelter for the residents as they might be affected by the smoke.

The only structure said to have been damaged was some sort of a picnic table at Tilden Regional Park, where about 100 children were present when the fire broke out. They were evacuated and have been waiting for their parents to pick them up, according to East bay Regional Parks, KRON4 reported.

Employees at the Lawrence Hall of Science, located at 1 Centennial Drive, and two other nearby facilities were asked to evacuate from the area because of the fire, according to San Francisco CBS Local.