What looks like an outtake from a zombie movie is a shot of a "dirty bomb" training exercise held yesterday in Richmond, California. More photos of the scene below.
Here's the official caption:
Soldiers and airmen belonging to the California National Guard's 49th Military Police Brigade and Homeland Response Force joined Richmond, El Cerrito, Berkeley and Contra Costa County first responders for a "dirty bomb" response exercise on April 11, 2015, in Richmond, California. More than 200 Cal Guardsmen and civilian agency first responders from across the region participated in the exercise, which involved an interagency response to the simulated discovery of a "dirty bomb" in Richmond.
Army National Guard photos by Capt. Will Martin; see the whole set at the California National Guard's Flickr stream.