CANADIAN, Texas, Feb 28 (Reuters) - Richard Murray choked back tears on Wednesday as he surveyed the charred remains of his mechanic's workshop and home of 50 years in the small Texas Panhandle town of Canadian. The previous night a sheriff's deputy had pounded on the door and ordered Murray and his wife Gilissa to evacuate as the state's second-largest wildfire on record approached their home. "The house is gone and all the cars are melted," said Murray, 72, shortly after he returned home Wednesday morning. "There's nothing left."The wildfire, raging northeast of Amarillo since Monday, has blackened 850,000 acres (344,000 hectares) of grasslands and timber since Monday and spread eastward across the border of Oklahoma, the Texas A&M Forest Service reported. At least one person, an 83-year-old woman in Hutchinson County, was reported by local media to have died in the blaze, dubbed the Smokehouse Creek fire. Firefighters had managed to car