"Crisscrossing Michigan are more than 3,100 miles of old wrought- and cast-iron natural-gas pipelines -- the type federal regulators consider the most at risk of corrosion, cracking and catastrophic rupturing. The state's two largest utilities have replaced less than 15% of these pipelines -- 542 miles -- in the past decade," according to an investigation by the Detroit Free Press.
Looks like you haven't made a choice yet.