After a failed induction at 36 weeks, a 26-year-old woman underwent cesarean delivery which was complicated by significant postpartum hemorrhage. The next day, the patient complained of severe perineal and abdominal pain, which the obstetric team attributed to prolonged pushing during labor. The team was primarily concerned about hypotension, which was thought to be due to hypovolemia from peri-operative blood loss. After several hours, the patient was transferred to the medical intensive care unit (ICU) with persistent hypotension and severe abdominal and perineal pain. She underwent surgery for suspected necrotizing fasciitis, but necrosis was not found. The patient returned to the surgical ICU but deteriorated; she returned to the operating room, where she was found to have necrotizing soft tissue infection, including in the flanks, labia, and uterus. She underwent extensive surgery followed by a lengthy hospital stay. The accompanying commentary discusses the contribution of knowledge deficits and cognitive biases to diagnostic errors and the importance of structured communications between professionals.