A transcription made of a White House tape recording dated May 5, 1971, documents that the planning phase of the Hard Hat Riot took place in the White House Oval Office. Colson is heard successfully instigating several New York State AFL-CIO union leaders into organizing an attack against student protesters in New York. These officials then armed some 200 construction workers in Lower Manhattan with lengths of steel re-bar which they, along with their hard hats, proceeded to use against about 1,000 high school and college students protesting the Vietnam War and the Kent State shootings. The initial attack was near the intersection of Wall Street and Broad Street, but the riot soon spread to New York City Hall and lasted a little more than two hours. More than 70 people were injured, including four policemen. Six people were arrested.