This never happened. And who would follow a god who punishes people for being skeptical? What a jerk! Even if the biblegod were real, a person who valued intelligence, morals, and sanity would never worship that god.
It has never been proven that the Flood absolutely never happened. Science has some unanswered questions about things from that time period, questions that the Flood event would answer but of course...let's not even consider that an option since "God-less scientists" say it can't be.
God doesn't punish people for wondering how things in the world work-- He gave people their ability to question, reason and wonder. EVERY single time in the Bible, when a person/person's started taking God out of the picture---that's when their REAL troubles began.
IMO, I don't think there is any real intelligence, morals or sanity without God. I have seen people possess multiple degrees, they think they are so smart and superior but what they've been learning...is a bunch of nonsense that is going to get them nowhere if there is an "afterlife".
Morals without God? I suppose it could remotely be possible but I happen to know there's an awful lot of immoral people even in the churches, so I dunno.
Sanity without God? That would depend on how one defines "sanity". IMO, Christianity is the only teaching that makes logical sense to me (and I've studied all the popular ones). If there is even a remote chance that what the Bible says is true then I think it would be completely insane to take a chance on dying and not have one's life right with God. Especially when the Bible says there will be NO second chances to make things right. Sanity says to "get it right while one still can", it seems to me like living in complete denial would be insanity.