I thought the exact same thing. From what I heard I believe there is a layer of glass a few inches down that prevents anyone from falling all the way in. Still, pretty shocked there hasn't been any major issues with this display.
@snowleopard Yeah, I had no idea! At first I missed the sign at the beginning of KOTK that mentioned the depth of the pool, and wondered why the pennies at the bottom of the pool were so small. My sister was visiting with me and she almost stepped in, assuming the tank was covered in glass! She realized it wasn't just in the nick of time, that could have been bad!
I always like seeing my family members from out of town who see this the first time. Their reaction is much the same, they can't believe this doesn't have barriers! And yes, there is a layer of glass that is under about 3 or 4 inches of water and you have to really look to see it.
