NYC was a shithole back then. It was held together with a police force with more funding than the entirety of the UK at the time. You couldn't drive 2 blocks without seeing a cop car.

When the power went out it immediately descended into looting and chaos by the usual suspects.

https://en.wikipedia.org/wiki/Northeast_blackout_of_2003

GTA 4 actually captured the vibe of post 9/11 NYC very well