Heartland Fire-Rescue crews were battling a two-acre brush of State Route 94 in San Diego's East County.
Several 10News viewers called in to report the sight of smoke spewing into the air of the highway, just before 1:30 p.m. Tuesday. The blaze sparked on a hillside near High Street along SR-94 and the SR-125 connector in La Mesa.
Heartland crews asked the public to avoid the area for at least two hours. The blaze was knocked down around 2 p.m. Crews said if they had experienced the same winds as last month, the result could have been very different.
One woman was placed in custody as a "person of interest" by San Diego Sheriff's deputies. Officials said she is a known transient and was in the area at the time of the fire.
Officials added that there are multiple homeless encampments in the area.
Investigators are still looking into how the fire started. No structures were threatened and no injuries were reported.