D.C. Fire and Emergency Medical Services spokesman Alan Etter said this is being treated as what he calls a "mass casualty" incident.
Ambulances are lining up in the area around 1990 I Street, Northwest, and a triage area is being set up at nearby Murrow Park.
There's no immediate word on what the problem is.
Stay with News4 and nbc4.com for the latest updates to this developing story.
.
Thank you...you found what I found
Carbon monoxide poisoning is my guess.
I am sure this will be spun as one of those "mass hypnosi" things like the plane a few months ago where 10 ppl got sick. They tried to say one person puked and started a chain reaction.