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Cindy Crawford opened up on losing her brother to luekemia when he was just 3-years-old. The model tells Oprah in a new video how the tragedy changed her family.

"I think when my parents first told us that my brother was sick, we didn’t really understand what it meant," Crawford says in the video. She was 8 when her brother Jeff, then 2, was diagnosed. "They didn't use the word 'cancer.'"

Crawford recalled taking two-hour drives almost every day to and from the hospital while her brother was receiving radiation treatment. Her parents made the decision to put their son in an experimental program in hopes it would save his life. Unforutantely, the treatment did not work and Jeff died at age 3.

"My mother said she found him sitting in his room. He was sitting at his little table, and she said, ‘What are you doing?’ And he said, ‘I’m praying.’ And she said, ‘What are you praying about?’ He said, ‘So that when I die, you’ll be OK.’ As a mom now, I can’t imagine hearing your child say that," Crawford shared.

Watch the preview below. "Oprah's Master Class" airs on OWN.