A cyberattack that knocked out the main oil pipeline supplying the U.S. Eastern Seaboard and the potential shutdown of a major Canadian conduit could send fuel prices soaring, the Financial Post reports The outage on the Colonial Pipeline could be exacerbated by a Michigan state order forcing Enbridge Inc.’s Line 5 pipeline — supplying oil to Michigan, Ohio, Ontario and Pennsylvania refineries — to shut down on Wednesday, which could further strain U.S. oil supply. Calgary-based Enbridge has vowed to defy the order and continue shipping oil through the line until forced to close by a court.