Watch Diana: The Ultimate Truth for Free: How to Stream the Movie Online at 123Movies. . Marking the 25th anniversary of the tragic car crash that killed her, this new ground-breaking documentary will examine the death of Diana, Princess of Wales. Twenty five years on, many questions around what happened, and who is responsible, still remain. Featuring exclusive never before heard interviews, former Detective and award-winning Investigative Journalist Mark Williams-Thomas, will examine some of the theories that have emerged since Diana’s death and will set out to answer key questions: Could Diana have actually survived the crash if she had been treated differently at the scene? And what impact did Diana’s explosive BBC interview have on the final years of her life? Did it set off a chain of events that actually led to her death?