Laura Prepon is mourning the unexpected death of her brother, Brad Prepon, who died last month at age 48. “He passed away suddenly from an unknown heart condition—it was a devastating shock.” Brad’s obituary described him as a lifelong student of history, with a particular fascination with World War II. According to the obituary, Brad moved to California in 2002 and settled in Costa Mesa. She has largely kept her family life private, making her tribute to Brad a rare glimpse into her grief.