The new year is starting with some sad news for the family of Natalie Cole and music lovers everywhere. The "Unforgettable" singer passed away on New Year's Eve, her rep confirms. She was 65 years old.
While the official cause of death was congestive heart failure, TMZ reports that Cole had been ill for some time now after complications from a kidney transplant and Hepatitis C. She had canceled several tour dates in December, including a New Year's Eve concert at the Disney Concert Hall in Los Angeles. 
“It is with heavy hearts that we bring to you all the news of our Mother and sister's passing," her rep says in a statement. "Natalie fought a fierce, courageous battle, dying how she lived..with dignity, strength and honor. Our beloved Mother and sister will be greatly missed and remain UNFORGETTABLE in our hearts forever.”
The nine-time Grammy winner and daughter of jazz icon Nat King Cole became a household name with the success of her debut album Inseparable, which included the massive hit "This Will Be (An Everlasting Love)." But the biggest hit of her career was "Unforgettable," her 1991 virtual duet with her late father. 
Cole struggled with drug abuse early in her career, a contributing factor to her Hepatitis C diagnosis. She was forced into rehab "kicking and screaming" by her manager in 1983, and after two stints became sober for good. 
Her music and spirit impacted her family, fans and especially her colleagues, who are sharing their grief of social media:

Our thoughts and prayers are with Natalie's family.