Carly Simon is in mourning after both of her sisters

The Broadway composer Lucy Simon and the former opera soprano Joanna

Simon both passed away this week, one day apart, leaving Carly Simon in sadness.

The two sisters of the "You're So Vain" singer,

whose father Richard Simon was a publishing tycoon and co-founder of the massive Simon & Schuster, 

reportedly passed away from cancer. Joanna passed away on Wednesday

from thyroid cancer, while Lucy passed away on Thursday after a protracted

fight with breast cancer. Joanna was 85 years old, while Lucy was 82.

According to reports, Lucy passed away at her Piedmont, New York, home, whereas Joanna passed away in a hospital in Manhattan.