Can't they put some rebar in the giant cement block? There are single hull oil tankers made out of steel heading to the scrap yard. They could cut a whole in the bottom of one and sink it over it. All I know is it needs to get plugged or contained. We can put a man on the moon 40 years ago, but can't plug an oil leak?
I guess as someone that treasures our coastal wetlands it is a touchy subject for me.