[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.