UPDATE: Donna Summer's family has released a statement confirming Summer's death and saying they "are at peace celebrating her extraordinary life and her continued legacy," the Washington Post  reports.
TMZ is reporting that Grammy-winning disco legend Donna Summer, famous for hits like "Last Dance" and "Bad Girls," died today at age 63 after a struggle with cancer.
Sources close to Summer tell us ... the singer was trying to keep the extent of her illness under wraps. We spoke to someone who was with Summer a couple of weeks ago ... who says she didn't seem too bad.
In fact, we're told she was focused on trying to finish up an album she had been working on.
Summer was a five-time Grammy winner who shot to superstardom in the '70s with iconic hits like "Love to Love You Baby," "Hot Stuff" and "Bad Girls."
She is survived by her husband, three daughters and four grandchildren.
Check her out performing "Hot Stuff" and "She Works Hard for the Money."