CBS Baltimore is reporting a possible active shooter at Walter Reed MMC in Maryland.
The report, seemingly confirmed from a tweet by Congressman Dutch Ruppersberger
I am currently at Walter Reed Medical in Bethesda where we’ve been told there is an active shooter. I am currently safe in a conference room w/ approx 40 others.
More info to follow.
UPDATE
An update from Department of Defense says it was just a drill, carry on.