To is a preposition. Die is a verb. “On the shitter” is a prepositional phrase.

Yesterday was Lenny Bruce’s Birthday. The man who transformed stand-up comedy from short gags about insurance salesmen and lady drivers to conversational musings about sex, death, race, religion and what it might sound like if Jimmy Cagney and Edward G. Robinson shared a cab. The man who made blasphemy constitutional, Lenny was one of the few pop culture figures to both revolutionize his art form and die on the toilet. The others being Elvis Presley and innovative sword swallower “Incontinent” Connie Karamazof.

Dig, man. Lenny paved the way.