A vacant house in south Modesto burned Monday morning for the second time in three months, leaving little more than portions of the frame. Modesto Regional Fire Authority crews responded to the home at 1227 Inyo Ave. just after 5 a.m. and found it fully engulfed in flames, which had caused half of the roof to collapse, according to Battalion Chief Randy Anderson. Crews started with a defensive approach, but after knocking back the flames, moved inside the home to search it and finish extinguishing the fire. It took about 45 minutes to contain the blaze. The house did not have any sheet rock, just bare wood stud framing, Anderson said. He said the house had burned once in July. An arson investigator responded to the scene, but the cause of the fire is still under investigation. The estimated cost of damage to the home is $95,000.