Marines treated after unknown substance found in envelope

Several Marines are receiving treatment after being affected by an unknown substance found in an envelope.

The envelope was received at Joint Base Myer-Henderson Hall, next to Arlington National Cemetery in Arlington, Va. The building where the envelope was opened was evacuated immediately.

An envelope containing an unknown substance was received, today,
aboard Joint Base Myer-Henderson Hall. Personnel in the affected building took immediate preventative measures by evacuating the building.

— U.S. Marines (@USMC) February 27, 2018

The Marines later tweeted that “several Marines” were receiving medical care.

A spokesperson for the Metropolitan Washington Airports Authority Fire Department said 3 people are being treated, according to ABC News. {mosads}

The Arlington, Va., fire department tweeted that 11 people began feeling sick after the letter was opened.

#Update: Ft Myer Hazmat, 11 people started feeling ill after letter was opened in consolidated admin building. 3 were transported. Condition not known. Ft Myer PIO enroute.

— Arlington Fire (@ArlingtonVaFD) February 27, 2018

Three of the patients the fire department transported are in stable condition, but an investigation is ongoing. 

#Update: Ft Myer, 3 transported patients in stable condition. Command is scaling back incident starting to put some units in service. Investigation ongoing.

— Arlington Fire (@ArlingtonVaFD) February 27, 2018