Actor John Travolta among celebrities, social media users to react to death of ‘Grease’ actress, singer Olivia Newton-John

Australian singer and actress Olivia Newton-John and American actor John Travolta as they appear in the Paramount film 'Grease', 1978. (Photo by Paramount Pictures/Fotos International/Getty Images) (Richard Davis, 2011 Getty Images)

Family, friends and fans around the world are collectively sharing a moment of sadness after news spread that Olivia Newton-John, a British Australian pop star who dominated the pop culture of an era, died after repeated treatments for cancer. Her family announced her death on Monday. She was 73.

News of her death was posted on behalf of her family via Facebook. The post read:

Afterward, heartfelt expressions swept social media, expressing both sadness and sharing favorite memories of the brave icon.

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Olivia Newton-John, superstar singer and actress, dies at 73

Here are some of the reactions, beginning with Grease co-star John Travolta.