captivate kids and parents alike. >> we were on our way out of the park when we decided to stop in and see tropic world. >> look at the monkeys. >> look at them running. >> it was very crowded. >> once we all got in there we all started to go through the exhibit. everybody is pretty much doing their own thing. >> suddenly, gasps of horror rise among the trees. >> i did hear a scream. didn't pay too much attention to it because the noise level that was already in there. >> chaos surrounds the gorilla exhibit. witnesses crane their necks to see what's happening. phil's heart beats faster as he rushes to the unfolding scene. >> i automatically started walking that way. i got in front of a zookeeper there who had a walkie-talkie, had it up to his ear and he started running. >> what happened? >> there was a lot of people there, people were running. >> the unimaginable has happened. every parent's worst nightmare, a 3-year-old boy, perhaps