While we have fortunately been spared natural disasters in the 100,000+ death category so far, we have had large disasters such as the Johnstown flood and the Galveston hurricane -- and we cleaned them up and went on.
The horror and shock gives way, and it becomes a problem that we can overcome... and we will. This terrible event, which is large, may well be dwarfed by another disaster's death toll.
In particular, we have quite a bit of seismically active ground and we could have a terrible earthquake at any time on either coast, or in the middle of the country -- and our preparations for another series like the terrible ones in 1811-1812 are woefully inadequate. Even another Charleston would be horrendous (though these days at least there is far less nuclear material about the Holy City than 20 years ago.)