but to see the entire southern part of the island engulfed that way, being there, it must have been hard to have any sense of perspective about how big this was. >> oh, it surprised us tremendously. it really -- it covered the whole lower manhattan. it was very surprising that the cloud was that big. came out halfway across the hudson river almost. >> when we look back at this now, what do you hope people take away from having this access to these -- what you saw that day? >> well, i hope that it gives them a better perspective of what happened that day. and it gives us an historical timeline of the events that occurred. you know, it's something we should never forget. it was a sad day. >> detective greg semindinger retired from the new york police department after 25 years, 20 years in the aviation unit. thanks for talking to us about this. i know you've had a lot of attention because of this. >> good to be here and glad the photos are out now. >> thanks. thanks for your service. ( sneeze )