The five-day-old wildfire burning out of control in the Los Angeles foothills and forest claimed its first victims on Sunday,two firefighters whose vehicle plummeted off the side of a road. The fire scorched 7,000 more acres since day break for a total burned area of 42,500 acres. The flames threaten 10,000 homes and are encroaching on the regions telecommunications nerve center. At least 18 homes have been destroyed. California Governor Arnold Schwarzenegger rushed back from Sen. Edward Kennedys funeral to survey the states worst fire,warning residents to heed evacuation orders for the very dangerous blaze. Flames could be seen stretching 15 miles above the heavily populated foothills,where an estimated 2,000 homes were under evacuation. Smoke mushroomed into huge clouds,some 20,000 feet high and visible from hundreds of miles away. What we have seen today was extreme fire behavior once again, Fire Commander Mike Dietrich said. But there were excellent saves made in the foothill communities,some darn good firefighting. The two dead firefighters were from Los Angeles County Fire and had been working deep in the Angeles National Forest Sunday afternoon when their vehicle careened down a slope. At nightfall,firefighters focused on Mount Wilson,the site of transmission towers for television and radio broadcasters and emergency services. Planes dumped water in the area,but Dietrich said the fire could reach the towers late Sunday or early Monday. More than 2,800 firefighters were on the ground,coming from as far away as Wyoming and Montana,trying to build more than 100 miles of fire protection lines. The fire that started on Wednesday above the exclusive community of La Canada Flintridge is only 5 percent contained and officials expected that,with hot temperatures and low humidity,it would grow larger. The cause of the fire is being investigated.