traveling across this country right now, atlanta is a hub. a lot of people connecting through atlanta, not only domestically but internationally. that airport for the last hour or so has been on lockdown and now we're learning the details of exactly what took place. walk us through what you know and kind of the trickle effect that you're seeing up here. >> reporter: yeah, yasmin, obviously, it was certainly a chaotic scene when people heard a gun ring out at the airport. we have learned that a passenger who was going through a main security checkpoint had a firearm, and during this process, just a short amount of time, was trying to reach the weapon and then that is when the gun went off and we have also learned from sources that the passenger who has still not been identified is still on the loose, and right now, authorities are trying to apprehend this individual, but you see the images right now on your screen.