someone had pulled the fire alarm. the next thing i heard, police car, sirens, just happened so fast. >> multiple fatalities, multiple injuries precise numbers not yet available. brian todd is over at the u.s. navy yard just outside. brian, what else are you picking up? >> reporter: wolf, picking up add the police presence here around this part of the perimeter. this is the easternmost side of the navy yard. these are d.c. metropolitan police officers here in tactical gear. we've seen multiple police officers moving up and down this part of the perimeter. there are some going down the street right there. also, we are -- we know from just visualizing, we've got fbi personnel here as well as atf personnel. there's been a park police chopper circling very low over part of the neighbor yard just to my left. i believe he's coming around for another pass. he's actually very low over there. we can't pick him up with a camera right now because he's