Flames raced down a steep hillside "like a freight train," leaving smoldering remains of homes and warnings that more communities should be ready to flee the wildfire churning through tinder-dry canyons in Southern California, authorities said. Planes and more than a dozen helicopters dropped water and retardant on the blaze sparked Friday that has destroyed 18 homes and blackened more than 34 square miles of brush on ridgelines near the city of Santa Clarita. About 300 miles up the coast, crews were battling another fire spanning more than 16 square miles outside the scenic Big Sur region. Near Santa Clarita, residents of some 1,500 homes were evacuated, and authorities have found a burned body in a neighborhood. Shifting winds were pushing flames northeast through Angeles National Forest, where additional evacuations were ordered in the city of Acton and other residents were warned to prepare to leave, authorities said yesterday. The fire has ripped through brush withered by days of 100-degree temperatures and years of drought. "It started consuming houses that were non-defendable," Los Angeles County Deputy Fire Chief John Tripp said, describing the flames as charging through terrain "like a freight train." Juliet Kinikin said yesterday there was panic as the sky became dark with smoke and flames moved closer to her home a day earlier in the Sand Canyon area of Los Angeles County. "And then we just focused on what really mattered in the house," she said. Kinikin grabbed important documents and fled with her husband, two children, two dogs and three birds. They were back at home yesterday, "breathing a big sigh of relief," she said. More than 1,600 firefighters were battling the flames threatening homes and commercial buildings. The blaze, whose cause is under investigation, sent up a huge plume of smoke visible across the region. The body of a man was discovered Saturday in a burned sedan outside a home in the fire zone. Los Angeles County sheriff's officials are investigating the death but said there was no evidence it was a crime. The fire destroyed sets at Sable Ranch in Santa Clarita, which has Old West-style buildings used for movie locations. It also forced a nonprofit sanctuary for rescued exotic creatures to evacuate 340 of its more than 400 animals, including Bengal tigers and a mountain lion.