Absolutely no idea as well. But really tho, god knows if it really fell down and knocked it's head...

I've seen another mysterious cockroach death in my dorm before, it was squashed in the tiny space between the bed and the wall. We didn't remember seeing a cockroach while moving the bed, and it doesn't make sense for the cockroach to squeeze itself to death trying to move through the tiny space... Still a mystery but I would rather not think of it. I hate cockroaches.