So these aquariums have a design factor of safety of 11?? And still regularly fail? To me, that shows something majorly wrong in the design/build process...

So these aquariums have a design factor of safety of 11?? And still regularly fail? To me, that shows something majorly wrong in the design/build process... Clearly some failure modes are not well understood/modelled. Planes, the safest transportation vehicle by far, have a design factor of safety of 1.5 for example. And even then, failures due to material stress are rather rare.