Has anyone ever have this happen?

today I went to change the table saw blade and when I unscrewed the nut
that holds on the blade, it was cracked in half.
I was thinking after I replaced the blade and installed a new nut what
would have happened if the nut broke in half while spinning.

I must say "in all the years of changing saw blades I have never seen or
heard of this happening".

Has anyone ever have this happen?