SANTA FE, New Mexico — The U.S. Forest Service’s own prescribed burn started a sprawling 2022 wildfire that nearly reached Los Alamos, New Mexico, the agency acknowledged Monday after a lengthy investigation. The Cerro Pelado fire burned in dry, windy conditions across more than 60 square miles and crept within a few miles of the city of Los Alamos and its companion U.S. national security lab. …Investigators traced the wildfire to a burn of piles of forest debris commissioned by the Forest Service. The burn became a holdover fire, smoldering undetected under wet snow, with no signs of smoke or heat for months, said Southwestern Regional Forester Michiko Martin. …The federal government already has acknowledged that it started the largest wildfire in state history. …The Forest Service last spring halted all prescribed burn operations for 90 days while it conducted a review of procedures and policies.