Here’s what we know:
—Joint Base Andrews in Camp Springs, Maryland, has issued an all-clear for most of the base after locking it down following a report of an active shooter.
—The base had previously tweeted that the incident was ongoing at the Malcolm Grow Medical Facility, for which an all-clear has not been issued.
—The base was was scheduled to conduct an active-shooter exercise Thursday.
—We’re live-blogging the news as it unfolds. All updates are in Eastern Standard Time (GMT -5).
At a news conference, Col. Brad Hoagland, 11th Wing and Joint Base Andrews commander, said the lockdown was initiated after reports of a real-world active shooter situation at the Malcolm Grow Medical Facility were miscommunicated before the scheduled active-shooter drill was able to begin.
The security forces emergency services team conducting a routine inspection of the facility were misidentified, he said.
“We take all threats seriously and reacted to ensure the security of those on the base,” Hoagland said.
He added: “Fortunately, this was not a life-threatening situation.”
The base has now tweeted that the “all clear” applies to all of the base—except Malcolm Grow Medical Facility.