> As the video states this was flagged by inspections 14 times over 7 years or so.

And the article starts by stating that the collapse was ‘without warning.’

Warning in this context means something obvious to the unsuspecting user that collapse is imminent. Like a building creaking or buckling minutes or hours before finally giving way.

I take that to mean there were no signs of imminent collapse, just sudden failure.

In engineering terms thats a mode of collapse, thing, not about people actually warning.

When we do design, we're generally designing things so that if it fails it does so in a way that doesn't suddenly all collapse at once, but first deforms for a while so people can get away.