World leaders expressed sadness and condolences after at least 151 people were killed in a crowd surge Saturday night in Seoul, South Korea. The tragedy occurred in Seoul’s Itaewon district during Halloween festivities when a huge crowd surged into a narrow downhill alley. At least 82 others were injured in the South Korea’s deadliest accident in years. U.S. President Joe Biden and first lady Jill Biden sent their “deepest condolences” to the families of the deceased.