A spokesman for the Coast Guard told reporters that reports that shots were fired on a boat on the Potomac river were incorrect. CNN first reported and then later retracted the story.

"We're charged with 7x24 365, all day, every day, all-weather security and safety on the maritime interests of the national capital region. We train every day. We have crews that are highly proficient, and this is a routine exercise. I don't think that our operational commander saw any reason not to train today," he said.

CNN based their reports on radio communications from the Coast Guard. The network didn't note that the Coast Guard would have prefaced their communications with notification that it was a training exercise.

"When they start this exercise, they first come on the radio, even though it's a Coast Guard working frequency, they announce 'This is a drill. This is an exercise.' they preclude all of their actions with that," said the spokesman.

This video is from CNN's Newroom, broadcast Sept. 11, 2009.