I watch the show "Kitchen Nightmares" and many restaurants on the show end up closed! All the effort that Gordon Ramsey put into these restaurants and they go back to hell! Here are a few....

Peter's-More than likely the owner drilled it deeper into a nightmare!
Purnima's (Dillon's)-More likely Martin returned and the economy (It was in New York and there weren't many businessmen eating there despite the clean kitchen)!
The Mixing Bowl-Economic and Manager Reasons
Seascape-Owner sold it, it was even mentioned in the episode.
The Olde Stone Mill...Still there!
Sebastian's-Family Issues.
Finn McCool's...Still there!
Lela's-Management.
Campania-If it wasn't there...there meatballs would!

I'll give you more, but the one on Sushi Ko's was kinda sad...that one may have been engulfed by the bad economy.

I wonder if Gordon Ramsey would ever see these guys again?