Firefighters and paramedics are responding to a US military base in Virginia on reports of an unknown substance reportedly contained in an envelope that was opened at the base on Feb. 27, 2018.
An emergency task force was sent to Joint Base Myer-Henderson Hall after an "envelope containing an unknown substance" was opened, according to a statement from a Marine Corps spokesperson that was cited by a Washington Post reporter.
At least 11 people fell ill and were being treated for symptoms that included nosebleeds and burning sensations. Three patients were taken to hospitals and were said to be in stable condition, according to the Arlington Fire Department.
A second statement from the Marine Corps on the evening of Feb. 27 confirmed the number of victims but made no mention of what caused the symptoms.
Engine 161's crew evacuated and decontaminated 11 patients from the hazard area, all evaluated by EMS-3transported to area hospital. All units have picked up, scene turned over to @FBIWFO @FBI pic.twitter.com/cAbNW75zOJ
— IAFF LOCAL F253 (@FortMyerFire) February 28, 2018
The building was evacuated and a decontamination station was deployed. The FBI and the Naval Criminal Investigative Service will be conducting a joint investigation, according to the Marine Corps.
Henderson Hall is located near the US Army's Ft. Myer and is the headquarters of the US Marine Corps. It is also located next to the Arlington National Cemetery and nearby the Pentagon.