The National Transportation Safety Board tweeted that its investigators were gathering information about the cause of the crash.
A construction worker, who asked not to be named, told Reuters he was working nearby when he saw the 400-passenger ferry slam into the pier.
The boat was backing up and hit something and that's when everything went crazy.
The ferry that crashed is run by Seastreak, a privately owned company that also holds the Interlake Steamship Company, Mormac Marine Group, and Moran Towing, the largest tug and barge operator on the East and Gulf Coasts, according to the company's website.
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