ServPro, Tink. Black mold is a bitch. Bleach does not kill it. And it is too dangerous to mess with.
So sorry you have that mess to deal with. My basement flooded a few years back when the power went out and the pump shut down mid-Nor'easter. A disgusting mess especialoly when three kitty litters overturned and sloshed everywhere.
Yuck.
And despite my best efforts black mold set in in the walls. Had to be removed.

Meantime, my decluttering efforts are paying off. I can actually see improvement. whoo whoo