Ethel Merman kissing her daughter-in-law, Barbara Colby.

On July 24, 1975, Colby and acting colleague James Kiernan were walking to their car following an acting class in Venice, Los Angeles, California, when they were shot inside a parking area. The murders occurred after three episodes of the TV series Phyllis had been filmed. Colby was killed instantly, but Kiernan was able to describe the shooting to police before he died of his wounds. Kiernan said that he did not recognize the two men who shot them and that the shooting had occurred without warning, reason, or provocation. They were walking to their car parked in this lot. It was normal for Barbara and pals to congregate in the parking lot after class and talk. Her friend actor Ron Rifkin would have been there too – but he stayed home sick that evening. They were approached by two black men in a light-colored van. Barbara and James were shot once. Neither were robbed. Police noted that there was no attempt to rob the pair and concluded that it was a random drive-by shooting or a targeted killing. The killers were never identified and the case remains an open cold case. At the time of her death, Colby was separated from her husband, Bob Levitt Six, son of Ethel Merman. Colby's final acting appearance was in the TV movie The Ashes of Mrs. Reasoner, which aired in 1976. Colby was cremated. Her ashes were taken to sea by family and friends and dispersed in a ceremony off Paradise Cove on the Pacific Coast.