I'm glad to find this forum as I've had some serious questions about the setting of the game. To the point, why are there so many car crashes and other destruction? It doesn't seem enough to say it's from the response. It looks more like this is the type of virus that strikes suddenly and kills within hours or minutes, But people are heard in the infirmary talking about how they're cured and the sickness is obviously a slower acting virus as it is being treated.
This seems like there should be more order. The show Last Man on Earth has a similar cause for the world's population dying off but there aren't car crashes all over the city streets. It seems more people would have died at home or in the hospital, their cars nicely parked. In truth the disaster aspects of the environment like crashed planes and overturned trains looks more appropriate to Fallout.
So, what scenario do the designers say played out? How did we get all of this destruction from a virus? As a disaster response trainer, I just gotta know!
Its not the virus that causes this, its Panic, rioting, looting and general break down of order in a densly populated area where people are trapped by the geography.
This happened over a failrly long period of time. The build up of rubbish in the streets. Cars running out of fuel will cause them to be abandoned. Crashes will happen as people try to escape rioters, gangs, cleaners. There is no way a situation like this would result in everyone dieing in a nice orderly fashion. The last man on earth is a load of rubbish. Have a look at how people behave in the show Containment.