After conducting her clinic and teaching a class, Mitchell complained of feeling tired on Friday 16 March. By the next day she had a throat complaint, leading to her being seen by local and later missionary doctors, and ultimately being diagnosed with diphtheria. She rallied at first, but died suddenly on 23 March 1917. A service was held in tribute to her on 26 March 1917, and she was buried in the Russian cemetery in Kurin, near to where her sister was living as a missionary wife. A local Christian leader, Elder Shang, spoke at her funeral service stating that "Our doctor has given her life for us. For twelve years she has been at the call of any one who suffered. She was like a man in her strength, and rose at any hour of the night or day to help us. Her name is known and revered through all this country."
