7:50 AM PT -- Jefferson Parish Coroner's Office tells TMZ Fats died of natural causes and his body was released to a funeral home. There was no autopsy.

Fats Domino, the legendary New Orleans singer and piano player who took the '50s and '60s by storm ... is dead.

Domino died in New Orleans, surrounded by friends and family, according to his daughter.

His hits were epic ... "Blueberry Hill," "Ain't That a Shame" and "I'm Walkin'."

Domino sold more than 65 million albums, and received a Grammy Lifetime Achievement Award in 1987. He was inducted into the Rock & Roll Hall of Fame in 1986.

He was deeply embedded in New Orleans, and did a lot of public appearances for relief efforts after Hurricane Katrina.

Domino was 89 years old.

RIP