Natalie Cole-Dead at 65 Years

Natalie Cole -- one of the great voices in decades -- has died ...

Cole, whose hits include "This Will Be" and "Unforgettable" which she performed as a virtual duet with dad Nat King Cole -- died from congestive heart failure, although we're told the underlying medical issues were complications from a kidney transplant and Hepatitis C.

Natalie had been very sick recently, cancelling several tour dates in late December including a New Year's Eve concert at Disney Hall in L.A. She also cancelled an upcoming February concert due to illness.

Natalie struggled with substance abuse and was plagued with health problems, suffering from liver disease in 2008. She also underwent chemo for Hepatitis C.

Natalie, who was married 3 times and has a son, was 65.

She died in a Los Angeles hospital.

RIP