VENTURA, Calif. (Reuters) - An unrelenting wildfire fanned by hot, dry Santa Ana winds threatened more than 12,000 homes in and around Ventura, California, on Wednesday, forcing thousands of people to race for safety. The fire, dubbed the Thomas Fire, raged in the foothills above and in the city of Ventura some 50 miles northwest of Los Angeles, fire officials said late on Tuesday, a day after it began.