Thanks to DCist for passing on video of one of the Transformers 3 cars (Bumblebee, if you follow that sort of thing, which I don’t) t-boning an MPD SUV that appeared to be rushing toward the scene of an emergency.
As you watch the video, the action isn’t on the street immediately in the foreground, but the street apparently in the background. You see an ambulance pass by the filming, then Bumblebee starts its cruise, followed by several other production vehicles, and then the SUV speeds into the intersection and the stunt car collides with it.
According to Fox 5, the officer driving the SUV is a bomb technician and was responding to the suspicious package call at 9th and F, but was using a different radio channel than the officers securing the filming location. You know, the extremely well publicized filming location.