New York before..

And beneath it all, a pulse. A crackle. A rushing, like the ocean. So much life and power. I suddenly felt as if I had been caught in a thunderstorm, one of scent and sound and roaring color rather than rain. It ripped into me and flowed through me, raised me up. After a day of vexation and disappointments, I abruptly realized that I was standing in the center of the greatest city the world has ever known..

And the New York after...

The crackle was still there, but it had ebbed. It was muted and distant, like flickering static on a television screen with its volume turned low.

Mobtown describes it properly.

Not trying to be sad, morbid or maudlin, but he describes the before and after of the NY energy better than I could.