AvatarNyssaoyeneyinblakeAvatarAvatarMusic icon Prince dead at 57verified_publisherCNNCNN — As stunned fans mourned legendary singer Prince, questions remained on what killed him days after he performed in Atlanta to rave reviews. Authorities are investigating the circumstances surrounding his death. An autopsy will be conducted Friday, starting at 9 a.m. CT (10 a.m. ET). Prince Rogers …