Carly Simon's Sisters, Composer Lucy Simon and Opera Singer Joanna Simon, Dead of Cancer a Day Apart

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Carly Simon is mourning the death of both her sisters, who died of cancer one day apart from each other.

Lucy Simon, a Tony Award-nominated Broadway composer, died of metastatic breast cancer Thursday at the age of 82, while Joanna Simon, an opera singer, died of thyroid cancer Wednesday at the age of 85.

Both deaths were confirmed to Deadline on Friday.

The trio's youngest brother, Peter Simon, a longtime photographer on Martha's Vineyard, died in 2018 at the age of 71 after being diagnosed with lung cancer.

A representative for Carly, 75, did not immediately respond to PEOPLE's request for comment.

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Lucy got her start in the music industry when she formed the iconic folk duo, The Simon Sisters, with Carly in the early 1960s.

After they released the song "Wynken, Blynken & Nod" in 1964, Lucy went on to attend nursing school and married David Levine in 1967. They share two children together, Jamie and Julie.

Lucy later returned to the music industry in the late '70s, and the couple would then produce two Grammy-winning children's albums in the '80s — In Harmony and In Harmony 2.

Lucy also received individual success when she became the third female composer on Broadway. Her score for 1991's The Secret Garden received a Tony nomination that year. Her second Broadway show, Doctor Zhivago, opened in 2015.

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Joanna also got her start in the '60s, debuting in Mozart's "The Marriage of Figaro" at the New York City Opera in 1962, according to Playbill. The mezzo-soprano performed at the Seattle Opera and with the New York Philharmonic, the Vienna Philharmonic and the Pittsburgh Symphony Orchestra throughout her career.

After retiring from the world of opera, Joanna became an Emmy-winning arts correspondent for PBS' The MacNeil/Lehrer NewsHour, a role she held until 1992.

Joanna was married to Gerald Walker from 1976 until his death in 2004. She was also with news anchor Walter Cronkite in the final months before his death in 2019.