A few weeks earlier, he had posted a plea on Facebook, looking for zombie volunteers. "Originally, my goal was to get 40, 50 zombies. In reality, with Facebook, I figured, 'If we get 10 … I could still work with 10 — 10 will be fine.' And then the number started to creep up on the invite page on Facebook. Two days before the event, we were up to 1,700 people.