I stood at that very enclosure with my own children less than three weeks ago. Were on vacation in Pittsburgh and never miss going to their wonderful zoo.
The enclosure has only one open side, the others are shielded by plexi-glass. The day we were there the best view of the dogs were through the glass.
There is a net below the open side...to catch, cameras, cups, trash and other small objects..keeps the animals from eating them and getting sick. It is not a safety net for people but a precaution to protect the animals. Most all open enclosures had this netting...for the animals protection, not people.
The top of the open side had a slanted top at a 45 degree angle sloping back towards the platform.
There were signs literally everywhere (not just at this exhibit), do not climb on rails, do not sit on rails, to not lean over rails, etc etc etc. Every single exhibit...signs signs everywhere signs. I do not think they could have put up more signs to fix it.
I like to think I would have jumped in after my child, but the reports I hear are the dogs were on him practically as he hit the ground. And 11 dogs that in the wild take down 500-800 pound wildebeests would have been a match for five or even ten people. Not sure how many people it would have taken to "save" the child but there just wasn't time or enough people. Anyone been attacked/bitten by one dog...imagine eleven of those on steroids. Later I am sure I would have wished I had jumped in and died too becasue living with what I had done would be worse than death.
I am just absolutely perplexed and how she could have been holding him that he slipped and fell over the edge. The edge is pointed you can't sit on it, it would hurt your bum. And if he was standing on it, he was standing on an edge less than a 1/4 inch wide...with his center of gravity way up above mom's ability to hold him.
I know 2 year olds can be slippery and I almost dropped my son a couple of times while just carrying him, due to him twisting or flopping about or hitting me in the face with his head. So maybe if she had him very close to the edge and he wiggled loose, but just holding him his feet would have been below the railing. ???????????
I actually hope there is video surveillance that we don't know about that shows what happened so how it happened can be determined with 100% accuracy and will not have a chance to repeat itself.
I just can't wrap my head around it...especially becasue I stood where she stood just weeks ago on a sunny day and watched the beautiful dogs.