get back! [ bleep ] >> i know -- there are multiple -- >> i know, get back! get in there! >> we see muzzle flashes from the mandalay bay! it's from mandalay bay. >> that, again, some video from body cams we're just getting in from first responders, among the first to arife on the scene. the president who is on his way to las vegas right now, he will meet with some of those first responder when he is arrives shortly. he'll also meet with some of the survivors of this attack. cnn's alex marquardt in las vegas and joins us now live. >> reporter: good morning, john. this is something we've seen so much of the president doing lately. visiting these scenes of heartbreak and tragedy. first after hurricanes harvey, irma, and maria, now after this worst shooting in modern u.s. history. the president and the first lady due to touch down in just around three hours' time. they will be making two stops here on the ground in las vegas. the first one, visiting a hospital where they will meet some of the 500 wounded in this attack, as well as the doctors who have been working on them.