1 . Seoul, South Korea — Most weekends, the narrow alleys of Itaewon, the neon-lit nightlife district in South Korea’s capital Seoul, are busy with partygoers and tourists. Now it’s the site of one of the country’s worst disasters.

At least 151 were killed in the crush, with dozens more injured. Authorities have now launched an urgent investigation to find out how what was supposed to be a night of celebration went so horribly wrong, as families across the country mourn and search for missing loved ones.

Here’s what we know so far.

Itaewon has long been a popular place to celebrate Halloween, especially as the holiday became more popular in Asia in recent years. Some even fly into Seoul from other countries in the region for the festivities.

But for the past two years, celebrations were softened by pandemic restrictions (防疫限制措施) on crowd sizes and mask orders.

Saturday night marked the first Halloween since the country lifted these restrictions – lending it particular significance for many eager young people in Seoul, as well as international visitors including foreign residents and tourists.

Hotels and ticketed events in the neighborhood had been booked solid in advance, and large crowds were expected.

Witnesses told that there was very little — if any — crowd control before the mass of people turned deadly.

Videos and photos posted to social media show people crammed together, standing shoulder to shoulder in the narrow street.

After the first emergency calls came in around 10:24 p.m., authorities rushed to the scene — but the large crowd of people made it difficult to reach those who needed help.

The thousands of people in Halloween costumes contributed to the widespread sense of confusion and disorder. One witness described seeing a police officer shouting during the disaster — but some celebrators mistook him for another partygoer.

The cause of the crush is still under investigation, though officials said there were no gas leaks or fires on site.