Cause of Indianapolis neighborhood explosion still a mystery INDIANAPOLIS, Nov. 12 (UPI) -- Citizens Energy, the Indianapolis utility investigating the explosion that killed two people and destroyed a neighborhood, said it has not yet found the cause. City officials said 80 homes were damaged in the blast Saturday in the Richmond Hill section of Indianapolis, and 30 may have to be demolished. The explosion killed a teacher and her husband, WISH-TV, Indianapolis, reported. While the cause has not been determined, Rep. Andre Carson, D-Ind., said preliminary findings of the Department of Homeland Security determined it was not a bomb or a meth lab that exploded. The utility company said there is no evidence of a gas leak prior to the explosion, but WISH-TV said it learned Monday a family living in one of the damaged homes may have noticed a possible odor of gas. When questioned Monday whether gas crews had visited or repaired gas lines at one of the demolished homes last week, spokesman Dan Considine offered no comment and referred questions to the Department of Homeland Security.