All the fish probably got sent to heaven because when sodium reacts with water, in addition to hydrogen gas which causes the boom, it generates sodium hydroxide.
I find it a bot strange that in english they always say “sodium metal”, as to imply there would be such a thing as sodium that’s not metal, but i never hear them say things like iron metal, carbon nonmetal or lithium alkali.
Fish just invented religion to explain the black magic that just happened