DENVER The Front Rage wildfire that tore through 15 square miles and destroyed 48 buildings, over half of which were homes, was human-caused, investigators said Friday. The Alexander Mountain Fire burning near Loveland, about an hour’s drive north of Denver, was one of several conflagrations that started up late last month and threatened urban areas north and south of the state’s capital city. Most of the wildfires have now been contained. One person was found dead in a burned building.