Clear the rubble, run a seismic radar, detect any airpockets, install constant underground radar across the entire island, create a museum on the site educatin

Clear the rubble, run a seismic radar, detect any airpockets, install constant underground radar across the entire island, create a museum on the site educating locals about geology/sinkholes. You can have the best engineers in the world, more frequent inspections, but if the foundation is ignored it will not matter.