A Times Square security guard stands in front of a U.S. national flag flying at half mast to mourn the victims of a mass shooting in Las Vegas, at Times Square in New York City, the United States, on Oct. 3, 2017. At least 59 people were killed and 527 others wounded after a gunman opened fire Sunday on a concert in Las Vegas in the U.S. state of Nevada, the deadliest mass shooting in modern U.S. history. (Xinhua/Li Rui)