"It was a medium to heavy brush that was burning, so you've got a lot of embers," said Insp. James Barnes from the L.A. County Fire Department.
Santa Ana winds were blowing, so crews went after the fire with all their resources. About 120 firefighters and three water-dropping helicopters battled blaze.
With winds losing strength, the helicopters were able to begin water drops before sunrise, keeping flames from spreading beyond the east side of the San Gabriel river bed. Though winds fueled flames early on, they also pushed them away from homes in the process.
Fire officials say they were fortunate for calm conditions that helped them gain the upper hand.
"We could have had a totally different scenario, but Mother Nature was kind to us this morning," said Barnes.
Shortly before 8:30 a.m., the fire was declared 100 percent contained. No homes or structures were damaged and no evacuations ordered.
One firefighter was treated for minor injuries, but no other injuries were reported.
The fire is being called suspicious. Arson investigators are looking into the cause.
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