Why did police/emergency workers vanish all at once?
If people only vanished when out of someone's eyesight, why did the emergency first responders vanish all at once? Some of them had to be looking at each other. And the dining room had all those uneaten plates of food, suggesting they'd all been served at the same time, then vanished at the same time. They had to have been looking at each other too, sitting at tables facing each other.
Why didn't the kids all disappear at the same time?