Fatalities during the war were not limited to the battlefield, as both first families discovered. The Davises lost five-year-old Joseph in 1864 when he fell to his death from their porch in Richmond. Water piped into the White House from the polluted Potomac River likely caused the typhoid fever to which eleven-year-old Willie Lincoln succumbed in 1862. Mary Lincoln grieved so intensely for Willie that her family feared for her sanity. She ultimately found comfort in spiritualism, which was popular in the mid-nineteenth century.