More than 150 people were killed in a crowd crush in the South Korean capital of Seoul on Saturday.
The devastating incident happened in the district of Itaewon, known as a party spot, where thousands had gathered to mark Halloween.
It was the first time the event had been celebrated for two years without strict Covid measures in place, but things began to spiral out of control around 11pm.
Officials are still trying to unravel exactly what happened, after 154 people died and 149 were left injured – 33 are in a serious condition. Here’s what we know so far.
What caused the crush?
Police are yet to find out exactly what triggered the tragedy, but it seems around 10.20pm on Saturday evening that people began falling in the crowd. Pressure from both ends of the six-metre alleyway in Itaewon also meant no one could get out.
Members of the public then began performing CPR on victims around 11pm, because health professionals could not reach everyone, according to the BBC, and ambulances couldn’t move through the crowd.
The first deaths were confirmed at 2.30am local time.
The police have since admitted that they failed to notice the crowd’s sudden surge.
Hong Ki-hyun, chief of the National Policy Agency’s public order management bureau, told local outlet Yonhap News: “It was foreseen that a large number of people would gather there. But we didn’t expect that large-scale casualties would occur due to the gathering of many people.
“I was told that police officers on the scene didn’t detect a sudden surge in the crowd.”
He said that 137 officers were deployed to the party district this year for crowd management, compared to between 37 and 90 in 2017, 2018 and 2019, but many of these officers were tasked with cracking down on illegal activity and managing traffic.
According to some accounts, 100,000 people were in the area and police were trying to stop some attendees going into busy areas.
There were also messages on social media in the run-up to the crush, with messages warning that the streets were overcrowded, and that some felt unsafe.
Attendee Nuhyil Ahammed told the BBC: “We always go to this alley. I don’t know why, but there are always good bars and people in costume.”
Later in the evening, it seemed something shifted, according to Ahammed.
“People began pushing from behind, it was like a wave – there was nothing you could do. Even if you were standing still, someone was pushing from the back and from the front.”
Most of the victims were in their 20s, and more were women than men. All the victims have already been identified by the police.
Around 26 foreign nationals are among the dead, according to Reuters, from 14 different countries.
What will happen next?
Prime minister Han Duch-soo has promised to launch a “thorough investigation” into what caused the disaster, and to implement institutional changes so such an accident does not happen again.
He said: “My heart is heavy and I struggle to cop with my grief.”
He added that he felt “responsible for people’s lives and safety” and will be leading a task force team handling the incident.
Footage from 52 different CCTV cameras and 44 witnesses are helping the police build up their investigation.
The government has promised to provide up to 15 million won (£9,100) for funeral expenses to the families of the victims.
For now, K-pop concerts and government briefings have been cancelled as South Korea is in national mourning, while schools and companies around the country have cancelled Halloween events.
The government is likely to be under pressure to increase safety standards and crowd control measures.
The prime minister also said there were incidents of people propagating hate speech by blaming victims, in addition to incidents involving the spread of false information online, which are being investigated by police too.