Pittsburgh Police have issued a warning to citizens this weekend: If you hear gunshots and apocalyptic explosions on the streets, they’re probably coming from the set of The Dark Knight Rises, which is currently shooting around Carnegie Mellon’s campus. Still, they want you to play it safe. So if you think there’s a chance the bazooka you just heard go off is real, call the cops and let them sort it out. Or if you want a more effective response, just go outside and shine the bat signal. [WTAE]