The architect (in ~2003) reckoned that you could shoot a bullet hole in the aquarium, and nothing but some water would leak out. Catastrophic failure was "impossible".
In the past, sometimes bridges have collapsed when there was wind of just the right frequency, so called unsinkable ships would sink (Titanic, although the true history, seems or might be that, that was not claimed). I used to have or came across (if I remember right), some C or D cells (possibly Ray-O-Vac), which said something like 'Absolutely 100% Guaranteed Totally Leak-proof', with huge amounts of horrible brown (glue like) goo, coming out of them, like crazy. Great pity I didn't photograph it!
Engineering is full of learning by dramatic failure. Hindenburg Airship disaster, oops we shouldn't have used Hydrogen, it can burn/explode (the fuller details, with flammable outer coverings and war-regime NOT being allowed to purchase US Helium, Static electricity being able to set it on fire, via mooring ropes etc, are probably the real factors, especially).

