Power Outages

[timecanwait.livejournal.com]

I don't know how to go about researching this without getting on a terrorist watch list, haha.

I'm trying to write a mass power outage into my story.  But I need to know:

• Would outages happen on a city by city basis, or could something happen to make an entire state lose electricity?
• If said outage were to happen, what could cause it?
• I'm sure this depends on the cause of the outage, but worst case scenario, how long would people be without power?
• What types of buildings have backup generators to insure they will still have power in case of emergency?  Hospitals and jails, I'm sure, but what else?  Would a bank have a backup generator to keep the alarms going and the safe locked if the power's out?

The story is taking place in the USA.  I Googled "National Grid USA" and found that there's a company by that name that manages just a few states.  So am I correct in assuming there is no large-scale utility authority that manages the entire country?  That's fine, it just makes my job harder, because I will have to write in several smaller outages instead of just POOFing everyone's electricity, haha.