A spine-tingling account of what happened when a Halloween night of celebration turned into a nightmare. More than 100,000 young revelers, who were packed into the narrow bar-lined alleyways of Seoul's trendy Itaewon neighborhood, became trapped in a mass panic. The toll was astonishing: 159 people, including two American students studying abroad, had suffocated and died that night. Nearly all those who perished were in their twenties.