Description from the Mod page:
Okay, here it is... Liberty city had been hit with an airborne virus that changed most people into zombies. It was the beginning of the end...
The city is in panic. Vehicles are running lights, crashing, running over pedestrians and zombies alike. Pile ups are frequent as well as vehicle breakdowns, tire blowouts, even car bombs. Traffic laws... huh, no such thing.
As you run down the streets it's not uncommon to see several "Slow" infected "limping"
along with slightly faster "hunched over" ones coming up on them. There are also "Runners."
Now it wouldn't be a true end of the world scenario without other armed civilians.
Survivors, should you choose, can be called in. They'll have your back. And if you don't have a use for them anymore, tell them you don't need them.
Other armed pedestrians are out there, so watch yourself... They may be in a car, on foot, in groups, or even a heli... And the question is who's side Will they be on?
How LONG do you WANT to survive the Liberty Infection?
Mod Page - http://www.gta4-mods.com/script/left-4-liberty-infection-v51-f17152