Coast Guard fires on boat in the Potomac?? The U.S. Coast Guard has fired on a suspicious boat in Washington DC's Potomac River, CNN has reported. The incident came as Americans mourned the eighth anniversary of the September 11 attacks on the Pentagon and the World Trade Center in New York today. The Coast Guard tried to contact boat, believed to be a recreational boat. However there was no radio response. The decision was then made to fire on the boat. It is believed that ten rounds were fired on the boat. The Potomac River flows past many of Washington's greatest attractions, including the Kennedy Center and the Washington Monument.