He must've felt and is still feeling horrible:
Itaewon crush: The policeman who tried to stop Seoul's Halloween disasterKim Baek-gyeom is still visibly shaken by what he saw on Saturday night in Seoul's Itaewon district.
An assistant inspector in the South Korean capital, he was on duty that night.
"We had received a report of an altercation in the area, so I arrived at the scene between 10.10pm and 10.15pm," he tells the BBC at his police station in Itaewon, just a few metres away from where the tragedy occurred.
He says he saw people lying on the ground, and heard screams. "I tried to do my duty, to help people. Unfortunately I wasn't able to," he says.
But a video shared on social media, showing his desperate efforts to divert people away from the alleyway, has earned him praise from South Koreans, even as it highlights the inadequate police presence on the ground that night.