In headlines it was called the “crush,” but survivors and witnesses described it more like the sea — a force that swept and sucked people into the crowd, brutally disappearing them. As news of it spread, parents, partners and friends desperately scoured social media for clues their loved ones were among those who had made it out of the fray alive. Later, bags, headphones, glasses and more than 250 pairs of shoes would be pulled from the scene — personal belongings amounting to some 1.5 tons — laid out at the Wonhyoro sports center, waiting to be claimed.

On the evening of Oct. 29, the course of hundreds of young people’s lives dramatically shifted when a crowd crush in the Seoul neighborhood of Itaewon killed 159 people and injured 196 others. According to South Korea’s Ministry of the Interior and Safety, 80% of those who died were in their 20s and 30s, and 12 were teenagers.

Almost a year on, a patchwork of colorful Post-it notes mark the alleyway where the tragedy unfolded. Sun-faded, they bear heart-wrenching messages: “I still miss you,” “Let’s meet in another life,” “We must NOT let this happen again.” This past week, the makeshift memorial was replaced with a more permanent art installation to mark the tragedy.