UPDATE: CNN has since confirmed that the situation was a false alarm and that an all clear was given at the base.
Joint Base Andrews, the military base located in Maryland just outside of Washington D.C. went into lockdown on Thursday morning after reports of an active shooter.
According to the Twitter account for the base, the alleged incident occurred at the Malcolm Grow Medical Facility on base.
According to CNN, the base had planned to conduct a drill during the morning of the events when authorities received a call of an active shooter.
Analysts on CNN speculated that a civilian could have called in a report of seeing someone with a gun, who was actually part of the exercise.
At 10:00 AM, CNN reported that they believed it was a false report.