[ChuckNorris89]

Bridges are outdoor subject to weather the forces of wind and the weight and harmonics of vehicles and people crossing them constantly.

A fish tank a relatively constant by comparison.

[gsatic]

The fish were having a race.

[danwee]

Gravity.

[ChuckNorris89]

Edited due to incorrect assumption.

[zimpenfish]

I'm no engineer but this would be static fatigue[1], no?

"[S]tatic fatigue occurs during prolonged and constant application of stress" (my emphasis) - much like the glass/acrylic at the bottom of a 14m high, 1M litre water column, say.

[1] https://en.wikipedia.org/wiki/Static_fatigue

[ChuckNorris89]

Interesting I didn't know that. Thanks for sharing.