its a zombie apocalypse. When you leave the school, there are zombies Everywhere. Limbs are scattered across the ground, blood is everywhere. Its like a horror movie. Some people are rarely immune, some aren't. Theres a virus, no one knows who created it..yet.
Some people are even half zombies. 
All we know is that the virus started in the school.
tips About the zombies: they cant see, they can only hear. most of them have lost a limb or two.
The police,or firefighters aren't coming.