The 1960 drama, an adaptation of James Agee's novel A Death in the Family, ran for over 320 performances and also earned a Tony Award nomination for Best Play, as well as a Tony Award for star Colleen Dewhurst. The play was adapted by Mosel for a feature film in 1963, starring Jean Simmons, and twice for television; once in 1971, with a script co-written by Mosel and Agee and starring Joanne Woodward, and once in 1981, for which Mosel did not write the teleplay, starring Sally Field.
Mosel's only other theatrical credit of note was a short-lived 1961 Off-Broadway musical entitled Madame Aphrodite, featuring a score by a young Jerry Herman, based on a 1953 teleplay for the Goodyear Television Playhouse.
Mosel wrote primarily for television and film; his major credits included the screenplay for Up the Down Staircase, starring Sandy Dennis, and the critically acclaimed PBS miniseries The Adams Chronicles.
There are no immediate survivors.