The Navy says an alert that was accidently sent out caused false reports of an active shooter at Walter Reed Medical Center.

Bethesda, Maryland — A mistake involving a mass notification system led to false reports of an active shooter at Walter Reed Medical Center and caused widespread panic Tuesday afternoon among doctors, visitors and staff.

The official U.S. Navy Twitter account confirmed that while preparing for an upcoming active shooter drill, a mass alert was accidently sent out without containing the words "exercise" or "drill."

Some people who saw the alert message, believing there was a real active shooter, immediately contacted the Naval Support Activity Bethesda (NSAB) security, which launched a full-scale response.

NSAB said security got a call around 2 p.m. Eastern about the 'active shooter situation' in the basement of one of the buildings at Walter Reed. Authorities with NSAB said crews cleared the building and found no indication of an active shooter.

The Navy and a Pentagon spokesperson initially claimed the false active shooter reports were part of a drill, but the Navy's investigation revealed that wasn't the case.

"On further investigation, they determined that the improper use of the system was the root cause and secured from the active-shooter response," the Navy explained in a tweet.

Security responded and cleared the building, finding no indication of an active shooter.



After investigating the call and the origin, NSA Bethesda has determined that this was a false alarm and not part of a scheduled drill as has been reported.



2/2 — NSABethesda (@nsabethesda) November 27, 2018

Many around the facility had been tweeting about the reported active shooter situation, including a Maryland congressman.

Congressman Dutch Ruppersberger, a Democrat who represents Maryland's 2nd Congressional District, wrote on Twitter that that he was in a conference room with approximately 40 other people when they were told there was an active shooter.

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. — Dutch Ruppersberger (@Call_Me_Dutch) November 27, 2018

After the Pentagon claimed the incident was a drill, he later tweeted that they were given the all clear but "at no point was there any indication that this was a drill."

Various employees inside the hospital had reported on social media about receiving notifications of a code white active shooter situation. The alerts urged people to shelter in place and move all patients and staff to secure locations.

From employee sheltered in place at Walter Reed.. when I asked what he is hearing/seeing. https://t.co/q1YlTV7Q1j — Adam Longo (@adamlongoTV) November 27, 2018

People were reporting that conflicting emails were being sent out addressing the incident at Walter Reed. Some emails said "exercise active shooter" while some said "this is not a drill."

Multiple officials said patients and staff were told to move to secure locations and were advised to remain on lockdown until notified by security.

A doctor at the hospital tweeted video showing heavily armed law enforcement officers in the area, but noted she hadn't heard any shots.

Inside Walter Reed right now after the active shooter announcement. Was looking on Twitter for news and it's filled with people questioning the safety of their loved ones. Building 19 in lockdown. Haven't heard any shots. Multiple agencies responding. Hopefully false alarm. pic.twitter.com/xNDKyEuN56 — Lindsey Migliore, DO (@DrMigliore) November 27, 2018

Another employee at the hospital posted a screenshot of a notification sent to her phone. She said she was currently hiding in a closet with a patient and two other employees.

Active Shooter at my job. Walter Reed Hospital. pic.twitter.com/ee3fXlqO6K — A'Jada 🧡 (@nattyby__nature) November 27, 2018