Natalie Cole has died of congestive heart failure at a local Los Angeles hospital, according to TMZ. She was 65.

The r&b singer is best known for her hit songs "This Will Be" and "Unforgettable," made famous by her father, Nat King Cole. She had fallen seriously ill in the last few months and cancelled December tour dates including a New Year's Eve performance at Disney Concert Hall in L.A.

"It is with heavy hearts that we bring to you all the news of our Mother and sister's passing. 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," Cole's rep told TMZ in a statement.

Cole underwent a kidney transplant in May 2009, according to the Los Angeles Times. She revealed her Hepatitis C diagnosis in 2008, which was the result of her drug use in the '70s and '80s. She successfully completed rehab for her heroin addiction in 1983.

The Grammy-winning artist married three times and had a son, Robert "Robbie" Yancy, who became a musician and toured with her.

Cole was a pre-med student at University of Massachusetts before she filled in for a friend in a local singing group. She soon put her studies on hold to pursue singing full time.