If there was any question as to why Raccoon City was decimated by a nuclear bomb, the new Resident Evil: Welcome to Raccoon City Web series should provide some insight. I always imagined that the residents of Raccoon City were oblivious to many things - particularly the evil Umbrella Corporation's participation in genetic experimentation and viral weaponry. However, the journalists in this "Introduction" video appear anything but naive. This is subjective journalism at it's finest -- full of sassy head tilts, news conference heckling, and direct questions asking why Jill is being sequestered and forced to stay in the city. I'm surprised they don't ask questions relating to Irons' penchant for human taxidermy.
What's cool about this fan-made series is that it's not linear in any kind of way. You can choose your own adventure with Chris Redfield, Jill Valentine, and Leon Kennedy. Sadly, Claire is missing from the pack.
Here's the Resident Evil: Welcome to Raccoon City introduction video:
Bonus: Here's the entire arc of Brian Irons in RE2: