2013 Boston Marathon bombings
In response to the bombings, security was increased in New York City. Counter-terrorism vehicles were sent to landmark sites in the city. Security was increased at Times Square, hotels, and other places. Security was also increased in Washington D.C., where the White House was partially evacuated. Pennsylvania Avenue was closed off by the United States Secret Service. In Chicago, all of the city's most important streets and buildings were also closed and inspected.