Itaewon crush: The policeman who tried to stop Seoul's Halloween disaster

"I saw a lot of people lying on the ground. People were screaming. You could see the pressure was increasing from the top of the alleyway."

Assistant Inspector Kim Baek-gyeom is still visibly shaken by what he saw on Saturday night in Seoul's Itaewon district.

"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.

"I tried to do my duty, to help people. Unfortunately I wasn't able to."

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.

In it, you see a lone young figure in uniform - deep worry on his face - frantically trying to stem the vast tide of bodies away from the narrow slope on which more than 150 people would ultimately lose their lives.

"People are dying!" he shouts desperately. "Everyone move this way - please co-operate!"

Inspector Kim wasn't even supposed to be there. Despite being based in the heart of Itaewon, he hadn't been deployed to the streets that evening.

Those streets would eventually be filled by more than 100,000 people, mostly young, who had come to enjoy a Halloween night out.

"I was at the station, waiting to be dispatched for any crimes which could occur in Itaewon that night," he says. There had been no mention of crowd control - either on the night or in the days leading up to Halloween.

"We received the report of the altercation near the alleyway, so I immediately went to the location."

This was when Inspector Kim saw the crowds were dangerously packed. People were being crushed at the bottom of the sloped alleyway that connects a main road with bar-lined streets on a hill.

To try to prevent more crushing at the bottom, he decided that he needed to stop people from entering at the top of the alleyway.

"As you can see in the video, I started shouting and asking people to move along to another place," he says.

Most of the people around him complied and in fact many started to help him direct the crowds. Soon dozens would be giving CPR to victims as crowd control efforts quickly turned into a rescue operation.

Inspector Kim says he did not see any other police officers on the scene, although he was later told others did take part in the rescue.

Working alone - without a megaphone or any basic plan of action - he was faced with the impossible task of trying to prevent a disaster as it unfolded in front of him.

The huge loss of life has left him with a heavy sense of guilt.

"I feel I didn't do my best. I didn't fulfil my duty as a Korean police officer and I'm very sorry," he says.

On Thursday, the mother of a victim contacted Inspector Kim to convey her gratitude for his actions on the night.

"I was too sorry to say thank you to her," he says.

"I couldn't do my job that night. If I can somehow meet the bereaved family members and express my apologies and talk to them, I would like to do that."

Those families' members now want answers as anger towards the authorities grows in South Korea.

On Wednesday, special investigators raided eight police stations across Seoul to gather evidence as part of a probe into how the crush was able to happen.

Proof is mounting of the authorities' failures. First, to properly plan for Saturday night and then, to effectively respond to emergency calls warning of overcrowding, which started coming in hours before the disaster.

In the days leading up to the tragedy, the local council, Yongsan-gu, held two meetings to discuss how to handle the Halloween festivities. According to its website, they discussed Covid-19, rubbish collection and illegal parking, among other things.

No mention was made about crowd control, despite the district mayor acknowledging the day before that this would be the first Halloween in three years without social distancing.

On Tuesday, South Korea's police chief admitted that his force's emergency response had been "inadequate" and that he felt "heavy responsibility" for the deaths.

The efforts of Inspector Kim, though, have drawn admiration from the general public. But he wants the focus to remain on the victim's families.

"A lot of people have contacted me and asked if I was OK," he says.

"But rather than worrying about me, think about the bereaved families who will be suffering the most. Please pray for them."