OAKLAND (KPIX 5) — Fire investigators on Thursday were trying to figure out how the fire that consumed 20 acres near Grizzly Peak Boulevard started Wednesday and whether it could have been arson.

The fire started on UC Berkeley land. Campus police said they’re investigating the incident as a possible arson.

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However, Cal Fire and the Oakland Fire Department are the agencies in charge of the fire investigation. They had a press conference an hour ago saying it is an open investigation and they have not determined the cause and origin of the fire.

Tree-felling crews continued to work at the scene of the East Bay hills fire into Thursday evening, bringing down trees that pose danger to firefighters battling the blaze in steep terrain, an Oakland fire spokesman said.

The fire, which was first reported at 1:05 p.m. Wednesday near Grizzly Peak Boulevard and South Park Drive, is 50 percent contained as of late Thursday morning.

About half of the fire is within Oakland city limits and the other half is on land owned by the Lawrence Berkeley National Laboratory, fire officials said.

Nearly 200 fire fighters were able to keep this vegetation fire to 20 acres overnight.

Oakland fire said crews were focusing on extinguishing hot spots.

Crews are working in “steep, challenging terrain” with large trees serving as fuel sources for flames, Oakland Fire Engineer Charleton Lightfoot said.

Fire crews will be removing pine and eucalyptus that either pose as major hazards for future spot fires or trees that have already been damaged.

“We have a variety of fuels that are situated here on this incident that make it complicated for us to get direct access with our hand crews to some of the areas,” said Lightfoot.

He said the goal by the end of the day is to have 100 percent containment and move to the “mop-up” phase of the fire.

“Mop up means there is still active fire occurring, but we have reduced and prevented spread and growth of this fire,” explained Lightfoot.

Temperatures will be slightly more favorable for fire crews because it will be a couple degrees cooler than yesterday. But Mother Nature still has fire officials a little concerned.

“A good amount of humidity that will pose as an issue for us, as well as the monsoon moisture that is associated with this time right now,” said Lightfoot.

That typically leads to thunderstorms. But fire crews remain optimistic that that won’t happen.

One Cal Fire firefighter suffered minor injuries after falling about 50 feet down steep terrain while battling the blaze, Lightfoot said. No other injuries have been reported.

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Grizzly Peak Boulevard will be closed between Centennial and South Park drives until at least 8 p.m. Thursday, he said.

Some neighbors say the eucalyptus and Monterey pine trees in the area remain a major threat. They want to chop down the non-native trees that are said to be more flammable.

These trees were scheduled to be cut down through FEMA’s pre-disaster mitigation grant originally in 2005. But FEMA walked away because of environmental opposition, said former UC Berkeley Environmental Manager Tom Klatt.

Others in the area have a different take

I think both parties are to blame, both the litigants who continually fight efforts to make our community fire safe and FEMA for buckling under that pressure, Jon Kaufman with the Claremont Canyon Conservancy.

Some are casting the blame on Dan Grassetti and his group, the Hills Conservation Network.

Grassetti has filed multiple lawsuits to stop UC Berkeley, Oakland and East Bay Regional Park officials from cutting the non-native trees and won all of the cases.

The organization even got FEMA to pull money it was about to give UC Berkeley to cut down the trees.

They want to use the fear of fire as a funding mechanism to advance an agenda that has very little to do with fire risk mitigation, Grassetti.

Grassetti took photos of the fire to support his points. He says the flames burned the ground vegetation, but not the eucalyptus.

This area was treated, said Grassetti. The fact that FEMA denied UC funding had nothing to do with it.

But one Cal Fire battalion chief working on the fire tells me off camera the eucalyptus trees have made the fire much harder to extinguish.

He points out that UC Berkeley has thinned out this eucalyptus grove, but these trees shed a tremendous amount of bark and debris.

He says the debris provided fuel for a lot of spot fires.

Fire department officials are advising people to avoid the area to allow crews to access the area of the fire without any trouble.

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