An incredibly stupid SCUBA diver moored his boat to a warning buoy and ignoring the clear markings of what lay underneith, decided to check out what was beneath it. The look-see didn't end well, dude was sucked in.
Now, after being oblivious to the close-by clearly visible cooling pond of the Port St. Lucie nuclear power plant, ignoring the clearly marked warning buoy, and getting WAY too close to a 16 foot (16 FOOT!) diameter intake pipe, this imbecile is suing the power company!
As the Slashdot linky suggests, Darwin just missed on this one...
https://goo.gl/ZxK7rB
Never enter an underwater structure unless you're absolutely certain you know it's condition and purpose.
A check with any of the local dive shops would have clued him in.