The Walter Reed National Military Medical Center has been on lock-down since around 11:00 a.m. July 6.
A call was placed to authorities from the center high rise building claiming a shot was heard.
Employees are following lock-down procedure and authorities are currently searching the campus.
Once a search of the high rise building has been completed a second search will be done with canines searching for explosives.
According to authorities evidence of a shooting has not been found.
More information as it becomes available.