Fire officials have determined the fire that gutted a single-family residence in Hathaway Pines yesterday was caused by hot ashes placed on the porch. Damage is estimated at $50,000. The blaze along Highway 4 at Commercial Way was first reported at 12:30 p.m. yesterday afternoon. Calaveras County Fire Captain Tom Hutchinson says the blaze was brought under control at 2 o’clock. No one was home at the time.