University of Michigan researchers have said a spill from Enbridge's Line 5 pipeline could be devastating to the Great Lakes make up one of the world's largest bodies of fresh water. Enbridge, however, has defied Whitmer's shutdown order, saying the pipeline hasn't leaked into the Straits once in its more than 65 years of operation. The company and its allies have said keeping the pipeline running is critical to energy security, especially in the wake of the Colonial Pipeline hack and shutdown.