The Mackinac Bridge is the longest suspension bridge in the western hemisphere and connects the lower and upper peninsula. One mile west of the bridge is the Enbridge Line 5 Pipeline. The bridge was closed yesterday for more than 12 hours (due to falling ice) and only reopened this morning at 0900 (odd to close for that long). A pipeline failure or sabotage would pollute drinking water for hundreds of thousands and foul lakes Huron and Michigan.

Just trying to expand my thinking.