[eerikkivistik]

> So, the bridge was under stress and moving(breaking off?) slowly by few mm each year causing the eventual collapse?

This is what it looks like from the data. The key here is "diverging paths", which means different parts of the bridge were moving in different directions, putting strain on it.

[n_ary]

> which means different parts of the bridge were moving in different directions, putting strain on it.

Thanks! But how was this not noticed[1] by the maintenance and renovation works? I would assume, such patterns should show visible cracks or some symptoms beforehand.

[1] I know that, for a huge structure, a few mm movement is tough to even notice without major equipment and monitoring, but still I believe inspections are done frequently for structural changes and damages.

[eerikkivistik]

Not sure. Perhaps a further investigation by the authorities will reveal the reason.