At least 146 people were killed and dozens others injured after a large crowd was crushed in a crowd surge during Halloween festivities in downtown Seoul Saturday night.

Videos posted on social media showed people performing chest compressions on others who were lying on the ground as ambulance lights lit up the street. The Associated Press reported that people were crushed to death after the crowd began pushing forward in a narrow alley outside Hamilton Hotel in the capital city’s popular Itaewon district. It wasn’t immediately clear what caused the crowd to surge.

Choi Seong-beom, chief of Seoul’s Yongsan fire department, said early Sunday that the death toll could still rise and that an unknown number of those injured were in critical condition, according to the AP. Many of the dead were sent to hospitals while the bodies of dozens of others who were killed were being transported to a nearby gym to be identified, Seong-beom said. Most of those killed or injured are in their 20s.

By THM