Americans observed Gun Violence Awareness Day on Thursday. Mass shootings have become very common in the United States, but the country remains divided over what to do about it. Some Americans want stronger gun controls. Others say people should be free to carry guns wherever they want to protect themselves. Three years ago, a group of teenagers from the South Side of Chicago launched a campaign. The group asked their classmates to honor Hadiya Pendleton, a victim of gun violence, by wearing orange shirts. The color orange represents the value of human life. The local action has grown into a national movement called Wear Orange. The hashtag #WearOrange can be seen all over Twitter and Facebook. Many famous American buildings or structures were lit up in orange on Thursday to help spread public recognition of the movement. One such building was the Empire State Building in New York City.