In 1993, Cassidy had a malignant mole removed from her back. Three years later, during a promotional event for the Live at Blues Alley album in July 1996, Cassidy noticed an ache in her hips, which she attributed to stiffness from painting murals while perched atop a stepladder. The pain persisted and a few weeks later, X-rays revealed that the melanoma had spread to her lungs and bones. Her doctors estimated she had three to five months to live. Cassidy opted for aggressive treatment, but her health deteriorated rapidly. In her final public performance in September 1996, at the Bayou, she closed the set with "What a Wonderful World" in front of an audience of friends, fans and family. She was subsequently admitted to Johns Hopkins Hospital.
Cassidy died at her family home in Bowie, November 2, 1996, at the age of 33. She was posthumously inducted into the Hall of Fame of the Washington Area Music Association. (Wikipedia)