Olivia Newton-John, pop singer who found stardom with 'Grease,' dies at 73

John Travolta Remembers Olivia Newton-John: ‘I Love You So Much’

Olivia Newton-John Remembered by Dionne Warwick, John Travolta & More: ‘We Are Forever Hopelessly Devoted to You’

Olivia Newton-John Dead at 73: John Travolta, Julianne Hough and More Pay Tribute