On the morning of September 11, 2009, the U.S. Coast Guard reportedly tried to stop a boat from "entering a security zone on the Potomac River" near the Pentagon. Immediate reports said shots had been fired. The Coast Guard later denied reports of shots fired. At the time, President Barack Obama was scheduled to attend a memorial event for the victims of the attacks on 9-11. CNN reported that the incident was a "training drill" by the Coast Guard. 
via mahalo.com
