In the early 80s the late Anthony Newley wrote, directed and starred in a new musical called "Chaplin" about Guess Who. The plan was to open it on the west coast for an extended tryout and then maybe a few dates as they came cross country, but it was to open at the New Amsterdam. Until this time the theatre had shown movies since the Depression.
The Nederlanders had site control and began to renovate. The roof garden was removed.They then discovered that the theatre would need a lot more work than a coat of paint so they walked away, but not before 'renovations' had left a nice hole or two in the roof.
If you watch the film "Vanya on 42nd Street" (just about the best Chekhov I have seen on film) you will see the water damage done in the preceding ten years or so. The play is shot all over the theatre. It isn't a "filmed play" at all, and one can see that the damage to the theatre is extensive. It is omnipresent. So whoever paid for the renovation/restoration got their money's worth.
The New Amsterdam was a viable if run down building until about 1982. All it took was 10 years of neglect to almost lose it.
By the way, Chaplin never made it off the west coast. It closed out of town.
"If my life weren't funny, it would just be true. And that would be unacceptable."
--Carrie Fisher