SEOUL, South Korea (AP) – South Korean police are investigating what caused a crowd surge that killed more than 150 people during Halloween festivities in Seoul last weekend. It was the country’s worst disasters in years. The Interior Ministry said Monday that police launched a 561-member task force to delve into details of the crush. Police say officers are analyzing footage taken by security cameras placed in the Itaewon area at the time of the crash and related video clips posted on social media. They were also interviewing witnesses to find exactly when and where the crowd surge started and how it developed.