On Monday, South Korean police investigated the cause of a crowd surge that killed more than 150 people, including 26 foreigners, during Halloween celebrations in Seoul. It was the country's worst disaster in years, and President Yoon Suk Yeol and tens of thousands of others visited special mourning sites.

Saturday's disaster was concentrated in a sloping, narrow alley in the Itaewon district of Seoul, a popular nightlife district, with witnesses and survivors recalling a "hellish" chaos with people falling on top of each other like dominoes. They reported that the entire Itaewon neighborhood was clogged with Halloween partygoers and slow-moving vehicles, making it impossible for rescuers and ambulances to reach the congested alleys in time.

The police have reportedly formed a 475-person task force to investigate the crush.

Officers have obtained footage from approximately fifty security cameras in the area and are also analyzing social media video clips. More than 40 witnesses and survivors have been interviewed thus far, senior police officer Nam Gu-Jun told reporters on Monday.

Other police officers have stated that they are investigating when and where the crowd surge began and how it developed. On Monday, a team of police officers and government forensic experts reportedly conducted a search of the Itaewon area.

Prime Minister Han Duck-soo stated at the beginning of a government meeting on the disaster, "The government will conduct a thorough investigation into the cause of the incident and make all necessary system improvements to prevent a similar accident from happening again."

Itaewon, renowned for its cosmopolitan atmosphere, is the country's most popular location for Halloween-themed events and parties, which have become increasingly popular among young South Koreans in recent years. There, an estimated 100,000 people gathered for the nation's largest Halloween celebration since the outbreak of the pandemic.

There were 26 foreign nationals among the dead.

Anne Gieske, a University of Kentucky nursing student from northern Kentucky who was participating in a study abroad program in South Korea, was one of the Americans killed, according to a statement from the university. The second was 20-year-old Steven Blesi, his father Steve Blesi wrote on Twitter after seeking information about his son.

After not hearing from his son, Blesi asked, "If anyone has any information, please share it." Following a deluge of responses offering support and assistance, he tweeted, "We have just received confirmation that our son has passed away," followed by, "Thank you for the outpouring of love. We require time to mourn."

Grace Rached, a Sydney film production assistant and Australian victim, was described by her family as "the life of the party." In a statement, her family said, "We are missing our beautiful angel Grace, whose infectious smile lit up the room."

According to Japanese media, among the deceased was Mei Tomikawa, who was studying the Korean language in Seoul. Ayumu Tomikawa, her father, told Japanese public broadcaster NHK that his daughter "really enjoyed her life in South Korea"

Itaewon's Halloween celebrations lack official organizers. Monday, South Korean police stated that they lack specific procedures for handling incidents such as crowd surges at unorganized events.

Saturday's Halloween celebrations required 137 officers to maintain order, significantly more than the 34-90 officers mobilized in 2017, 2018, and 2019 before the pandemic.

Citing these numbers, police dismissed as "different from the truth" rumors that a police station in the area was understaffed because it was providing Yoon, who relocated the presidential office to a location near Itaewon, with additional security. According to them, security for presidents has been provided by two special police units that have nothing to do with the Yongsan police station, which has jurisdiction over Itaewon.

According to some eyewitnesses, the stampede was caused by individuals in the upper portion of the downhill alley pushing those in the lower portion. Local media also questioned a lack of apparent safety preparations for the anticipated large crowd in Itaewon.

When questioned about these possibilities, Nam, the police officer, stated that the investigation would examine all potential causes for the crush.

As of Monday morning, the government reported that 153 of the 154 bodies have been identified and that relatives have been notified. Nearly two-thirds of the 98 deceased were female. It was reported that 149 others remain injured. The death toll could rise further as 33 of the injured are in critical condition, according to officials.

More than eighty percent of the deceased were in their twenties or thirties, and eleven were teenagers, according to the Interior Ministry.

According to the ministry, five victims were from Iran, four were from China, four were from Russia, two were from the United States, two were from Japan, and one victim was from Australia, Norway, France, Austria, Vietnam, Thailand, Kazakhstan, Uzbekistan, and Sri Lanka.

As the identification of the deceased neared completion, it was anticipated that bereaved families would begin planning funerals for their loved ones. The government, according to officials, will provide the necessary support for funeral procedures.

President Yoon declared a week of national mourning on Sunday and ordered flags to be flown at half-staff at all government buildings and public offices.

On Monday, the government inaugurated memorial sites in Seoul and other major cities. Tens of thousands of individuals, including Yoon and other high-ranking officials, visited the sites, laid white flowers at their feet, and bowed deeply. Near an Itaewon subway station, numerous individuals also placed chrysanthemums, bottles of Korean "soju" liquor, candles, and snacks, and posted numerous condolence messages.

Many hotels, department stores, amusement parks, and other businesses canceled Halloween-themed events after the disaster.

The crowd surge was the deadliest disaster in South Korea since 2014, when 304 people, primarily high school students, perished in a ferry sinking.

The sinking revealed lax safety regulations and regulatory shortcomings. It was partially attributable to excessive and improperly secured cargo and an unprepared crew for emergencies. The public will likely scrutinize what government officials have done to improve public safety standards since the ferry disaster in light of the deaths on Saturday.