So, wait, it's dangerous enough that the drunks shouldn't be there... but we're going to put a lifeguard there? I would hope that the lifeguard job comes with a huge life insurance policy for the next of kin.
I think that society owes people only so much protection for their own actions. (And to be clear, I'm not talking about the family in the original attack. Let's assume, whether you agree it should have been so or not, that no one was really aware of the danger a month ago. Now we are, and the warnings are posted. Temporary fences are up, with the promise of more permanent ones to come.)
Who do we put in danger-- some 20 year old kid taking a job as a lifeguard or someone who gets so plastered that they ignore the warnings that are now abundantly posted?
ETA-- And, while we're at it, shouldn't we post a lifeguard at each and every dock in the entire state of FL?? This isn't a problem limited to the waters of WDW; the locals and tourists in FL are facing the same dangers-- and those dangers are nothing new.