The 1200 block of New York Ave. NW is closed at this hour, following what appears to have been a fatal collision between a cyclist and a security vehicle associated with the Nuclear Security Summit.

The cyclist, who is believed to be female, was struck at the intersection of 12th Street and New York Ave. NW, D.C. Fire/EMS spokesperson Pete Piringer said. Piringer could not confirm that the woman had died, but he said it looked like a fatality.

Details are still somewhat scant, but WJLA’s Jennifer Donelan is reporting that the woman was crushed under a humvee, and that the vehicle was in the area to block off a road for a motorcade when it happened. The neighborhood around the Washington Convention Center is filled with such security personnel, military vehicles and barricades for the Nuclear Security Summit taking place today and Tuesday.

D.C. Police are on scene investigating as we speak. We’ll have more on this story as we learn it.

UPDATE 8:05 p.m.: D.C. Police now confirm that the cyclist, a woman, has in fact died. We still do not know her identity.