This case study report examines the critical incident surrounding the death of Ruby, an 80-year-old patient who died from sepsis caused by aspiration pneumonitis after a nasogastric tube was misplaced in her lung. The report details Ruby's medical history, including Alzheimer's dementia, diverticulitis, and a UTI, which were considered contributing factors. The analysis covers the timeline of her hospital admission, nursing observations, and medical interventions, highlighting potential medical negligence in her care. The report evaluates the Harm Score, indicating the severity of the incident and emphasizing the need for thorough documentation and evaluation of patient care to prevent similar incidents. It concludes that a series of oversights and failures in monitoring Ruby's condition ultimately led to her preventable death.