All-Clear at Joint Base Andrews

The base in Maryland lifted its lockdown after it instructed all personnel to shelter in place because of a report Thursday of an active shooter.

Malcolm Grow Medical Facility at Joint Base Andrews (Airman 1st Class Aaron Stout / U.S. Air Force)

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).

11:46 a.m.

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.”

10:44 a.m.

The base has now tweeted that the “all clear” applies to all of the base—except Malcolm Grow Medical Facility.

10:39 a.m.

Joint Base Andrews has issued an all-clear:

10:28 a.m.

It looks increasingly like the report of an active shooter at the base was a hoax. Although no official word has yet come down on this, several news reports have suggested the calm demeanor of everyone involved in the aftermath of the report suggests this was a drill all along.

10:12 a.m.

Jeh Johnson, the Homeland Security secretary, told a Senate panel he may be called out of his testimony because of the “unfolding situation” at the base.

10:01 a.m.

We have more from Joint Base Andrews:

9:58 a.m.

Joint Base Andrews is just outside Washington, D.C., in Prince George’s County, Maryland. It is the home of Air Force One, the presidential plane. President Obama reportedly did not have plans to use the base today.

There were questions earlier Thursday about whether the lockdown at the base was a drill, as one had been planned for today, but the Joint Base Andrews said while “an active shooter exercise” was planned, “reports of a real-world active shooter situation were reported.”

9:40 a.m.

There are reports of an active shooter at Joint Base Andrews in Maryland, and all personnel have been asked to shelter in place. The base is on lockdown.