The U.S. Coast Guard is still investigating what happened Friday night when Portland-based ferry ran aground about half a mile southeast of Basket Island in Casco Bay.

Ninety-six passengers were evacuated from the ferry, Bay Mist. There were no reports of pollution or injuries. The incident occurred around 10 p.m. Friday.

The 84-foot ferry refloated with the incoming tide around 3:15 a.m., and an inspection of the hull showed no signs of a puncture. The ferry and its three crew were escorted by tug to the Casco Bay ferry dock in Portland.