Transcript for 'She was religious in putting on her seat belt:' Princess Diana's sister speaks outWe swish genevas and turn to a new documentary about princess Diana where we hear from her older sister and the question she still has about the night Diana died 20 years ago. It's not often we hear from Diana's sister but she and others in the family are commemorating her death speaking candidly about their grief from 20 years ago. Often avoiding the spotlight princess Diana's eldest sister lady Sara shares openly about her torment the night of her crash. Reporter: More from that rare interview and others in the royal family in the but bbc documentary "Diana: Seven days." She was religious in putting on her seat belt.

Source: ABC News August 28, 2017 12:37 UTC