Firstfall
So, 191.9 AZAH has decided to dub this tragedy "Firstfall"—I guess the editors there think this creature is one of the mythical Firsts. Which seems suspect, considering it is very dead and clearly not some ageless god. Still, I suppose it's evocative.
I've heard other names as well. Some street mystics are calling it the "Blood Tithe." No joke. It feels dirty to even write that right now, with so many people wondering about the fate of loved ones. But that's not all I've read and heard. It's not the worst, for sure.
Here are a few more: "Corpse Collapse," "The Breaking," "Judgement's Drop," "Doomfall," and probably most tasteless, "West End Wipe Out" (that was from the always cringeworthy Lovat Star Journal, btw if you want to send hate mail.)
Firstfall seems to be the one that caught on. So Firstfall it is, I suppose.