SOUTH LAKE TAHOE — Investigators looking into the cause and origin of the fire that destroyed two South Lake Tahoe homes last week have determined it was accidental, said Lake Valley Fire Protection District Fire Chief Gareth Harris. Watercolor artist E. Peter Darvas, who owns the house where the fire started, sent an email to the art community on Tuesday describing the fire as a freak accident caused by an antique wood-burning stove he kept in his studio at 3120 Pioneer Trail. He was in an adjacent room cutting boards for a crate to ship a painting when he smelled …