We played again on Monday.
I was a idealistic cop, we had a 10-year old Latchkey kid, a sex addict and an African-American nerd.
We never really explained how the zombie plague started, it just started with zombie sightings down town.
When the zombies evolved, they evolved to be able to fly helicopters (we don't know what else they could pilot, not even cars, it never came up).
I never got a chance to sacrifice myself to save others, I died too soon.
There were a couple of funny moments, but we did a decent job of playing a more serious game.
Also, instead of the African-American being the first to die, they were the first to escape!
the kid escaped too, everyone else died horribly, bitten on the upper body and devoured by horrible zombies.

That's interesting development from last session. Repeatedly playing the game tends to broaden the horizons, for sure.