Washington, January 20 : `Grease' actress Olivia Newton-John has insisted that her friend John Travolta and wife Kelly Preston be left alone as they mourn the tragic death of their son.

The heartbroken celebrity couple bade their 16-year-old Jett a final goodbye after the teenager died from a seizure during a family holiday in the Bahamas on January 2.

The singer expressed her sorrow over the tragedy and urged the media to respect the family's privacy.

"I think it''s time to leave people alone when they are grieving. And I just send him a lot of love," Contactmusic quoted her as saying.

"It''s the worse thing that can happen to a parent. I send love to him and Kelly," she added. (ANI)