On her sixth birthday 80 years ago, Shizuko Nishio clung to her mother as US B-29 bombers started a firestorm that turned humans to ash and Tokyo into a wasteland. At least 80,000 people died, according to Japanese and US historians. Five months before the United States dropped atomic weapons on Japan's Hiroshima and Nagasaki, the nighttime raid on March 9-10, 1945 was World War II's deadliest using conventional bombs. IMAGES AND SOUNDBITES ARRANGED IN SEQUENCES