Sinden, known for his classical roles, appeared on Broadway in London Assurance.
Crewe is best known for his numerous hits for Frankie Valli and the Four Seasons.
Rivers was 81 years old.
Del Rossi worked at the theater for 40 years.
Mallory, who was 64, had been battling pancreatic cancer.
Wilson's musical was responsible for the American stage debut of Julie Andrews.
The 1940s Hollywood leading lady and wife of Humphrey Bogart achieved great success on both stage and screen.
The Oscar-winning stage and screen star was 63 years old.
Keating is best known for his performance as Carl Hutchins on Another World.
The theater and television favorite is known most recently for her work on NBC's 30 Rock.