Firefighters are making progress in their battle against a fire that erupted in an area near the northern San Diego County community of Pauma Valley Tuesday. Cal Fire officials confirmed Wednesday morning that the Agua Fire has burned at least 50 acres and is 40 percent contained. About 100 firefighters are expected to continue the firefighting efforts on Wednesday. The fire erupted shortly after 2:30 p.m. in the 13800 block of state Route 76 near Pala Road, northeast of Escondido. In addition to ground crews, Cal Fire used fixed-wing aircraft and water-dropping helicopters to fight the fire. No major evacuations were ordered, and officials said no structures were immediately threatened by the blaze.