Enbridge and the Environmental Protection Agency estimated the pipeline discharged more than 840, 000 gallons of oil into Talmadge Creek, which feeds into the Kalamazoo River, which in turn flows from near the city of Battle Creek into Lake Michigan.

CNN: STORY HIGHLIGHTS

The stock moved lower after the Environmental Protection Agency warned the energy firm it must stop the flow of oil from its leaking pipeline outside of Chicago by noon on Monday.

FORBES: After Hours: Utility's Shares Attempt Recovery

Of course, the loss of patent protection for Lipitor is one issue, and no one knows how well their pipeline drugs will be able to pick up the slack.

FORBES: Pfizer Learns To Live With Leaner Lipitor Cash Cow