shutting down part of the 101 hghway for a second milies fce the fire races down the hills towards the see. matt gutman is in california. reporter: tonight, with those flames encircling homes, the urgent aerial fight to save them. the alisal fire roaring down from the mountains, chewing through more than 15,000 acres and cutting off one of california s most important freeways, the 101 in santa barbara county. the fire driven by ferocious winds, as we discovered early tuesday. the wind here has been the story. these gusts have been up to 35, 40, even 50 miles an hour. those winds already grounding firefighting aircraft for a time. now shifting. it s the most critical time, because the fire will change directions on us. reporter: families evacuating through tunnels of smoke and flame on the 101.