According to the statement given by the police, Zack was found by his mother. Preliminary investigations suggest he had slipped on the remains of a rotting carcass, seemingly that of a rat, falling face first onto his desk's edge fracturing his frontal lobe and parietal bone. His body was found to be drenched in what appeared to be moldy coke, however further investigations to his untimely death are pending. Fans of Zack speculate on the possibility of foul play, a setup perpetrated by the "woke left", however these wild accusations are largely unfounded.
RIP BOZO NOW MY YOUTUBE RECOMMENDATIONS WILL BE CLEAN 
To quote the World of Warcraft South Park episode, "How do you kill that which has no life?"