The hospital and the emergency room have remained open during the investigation.
No significant safety hazard has been reported but those heading to the hospital should expect police and fire department activity in the area.
Update at 2:15 p.m. — The incident was prompted by a “suspicious package received in the mailroom” of the hospital, according to Arlington County Police Department spokeswoman Ashley Savage.
Update at 1:10 p.m. — The “all clear” has been given.
— ArlingtonCountyPD (@ArlingtonVaPD) May 2, 2017