Sadako was at home when the explosion occurred, about one mile from Ground Zero. In November 1954, Sadako developed swellings on her neck and behind her ears. In January 1955, purple spots had formed on her legs. Subsequently, she was diagnosed with leukemia (her mother referred to it as “an atom bomb disease”). She was hospitalized on February 21, 1955, and given, at the most, a year to live.
On August 3, 1955, Sadako’s best friend Chizuko Hamamoto came to the hospital to visit and cut a golden piece of paper into a square to fold it into a paper crane, in reference to the ancient Japanese story that promises that anyone who folds a thousand origami cranes will be granted a wish by a crane. A popular version of the story is that Sadako fell short of her goal of folding 1,000 cranes, having folded only 644 before her death, and that her friends completed the 1,000 and buried them all with her. This comes from the book Sadako and the Thousand Paper Cranes. An exhibit which appeared in the Hiroshima Peace Memorial Museum stated that by the end of August, 1955, Sadako had achieved her goal and continued to fold more cranes.
Though she had plenty of free time during her days in the hospital to fold the cranes, she lacked paper. She would use medicine wrappings and whatever else she could scrounge up. This included going to other patients’ rooms to ask to use the paper from their get-well presents. Chizuko would bring paper from school for Sadako to use.
During her time in the hospital her condition progressively worsened. Around mid-October her left leg became swollen and turned purple. After her family urged her to eat something, Sadako requested tea on rice and remarked “It’s good.” Those were her last words. With her family around her, Sadako died on the morning of October 25, 1955 at the age of 12.