Stephanie Fae Beauclair was born with a life-threatening abnormality, hypoplastic left heart syndrome — a missing left half of her heart. There was no way she would be able to survive on her own, and doctors confirmed there was no way to save her. All doctors save for one — Leonard Bailey, MD, who happened to specialize in fetal and infant heart issues. He proposed to Teresa, Stephanie’s mother, an extraordinary experiment, a transplantation of a baboon heart into the baby. Such a procedure was extremely rare — only three other humans received heart transplants from animals, and none of them survived their third day — but with nothing left to lose Teresa agreed.

On this day, October 26, in 1984, doctors and surgeons at at Loma Linda University Medical Center in Loma Linda, California transplanted a baboon heart into “Baby Fae.” She survived past her third day, and past her first two weeks, but then for reasons still unclear, her vital organs started shutting down.

Bailey was criticized by fellow medical scientists for his “wishful thinking” in performing such a radical procedure — that he not only did not attempt to find a human substitute the criticism went, but it was likely that the heart was rejected as a foreign body. Subsequent investigations found the baby had a different blood type, which raised the immune system, a “tactical error” that led to “catastrophic consequences,” as Bailey admitted.