Denise Darvall was seriously injured in a car accident on Main Road in Observatory, Cape Town. She and her family were visiting friends for afternoon tea and went shopping for cake. She and her mother were run over by a driver who failed to see them. This was due to a large truck that obscured his view of them, and their view of his car. Her mother died immediately. Denise Darvall sustained a skull fracture and severe head injuries after the car flung her across the road; her head hit the wheel cap of her car. She required life support to remain alive, and was essentially brain dead by the time she made it into the hospital. At 9 p.m. on the day of the accident, the resuscitation team stopped attempts to revive her.
Father gives permission
Edward Darvall arranged for his fourteen-year son, who had witnessed the accident, to be taken away from the hospital. The 66-year-old Edward was also given a sedative, and he waited while doctors attempted to save his daughter. Two doctors, Coert Venter and Bertie Bosman, informed him that there was nothing further they could do for Denise. Bosman explained that there was a man in the hospital they might be able to help, and asked Edward if he would consider allowing them to transplant Denise's heart. Edward Darvall later said that, after thinking about his daughter for four minutes, he reached his decision and gave permission. The public record shows that Edward Darvall mostly shunned publicity. He had undergone major stomach surgery, but his strength of character and dignity earned him many admirers. Before the joint funeral of his wife and daughter, he asked for donations to be sent to the Groote Schuur cardiac unit. Darvall was present at the trial of the drunk driver who was convicted of murder. Darvall, heartbroken, made a statement through a lawyer, asking the magistrate to show the “greatest possible mercy” to the driver. "The tragic death of his daughter was not meaningless, but benefited humanity," he said.
Declaration of death
Surgeons had a serious ethical problem because death then could only be declared by whole-body standards. The Harvard Criteria of Brain Death was not developed until 1968, nor was it adopted in South Africa or elsewhere for some years. The problem in this case was that, although Denise's brain was damaged, her heart was healthy. Various reports over the years attributed conflicting reasons for her heart stopping. For 40 years, Barnard's brother Marius kept a secret: rather than wait for her heart to stop beating, at Marius's urging, Christiaan had injected potassium into Denise's heart to paralyze it. This rendered her technically dead by the whole-body standard.
Organ donation
After her father gave his consent, Darvall's heart was donated to Louis Washkansky. Her kidneys were given to 10-year-old Jonathan van Wyk. Due to apartheid, the kidney donation to Van Wyk was controversial because he was khoi, while Denise was white. Washkansky lived 18 days before succumbing to pneumonia.