Comment Caltrans Says (Score 5, Informative) 407
The engineering authority in charge of the bridge and repairs already gave their answer to this on the morning news (yesterday, I think):
They found the crack. They designed the "band-aid": the saddle, T-bar, rods, etc. They had it fabricated and installed.
In subsequent days, they went back up to look at how it was doing. They found that it was vibrating more than they thought it should: it wasn't as rigid as it was designed to be. They recognized that this would lead to fatigue and failure.
They began designing the improved "band-aid" and planned to install it sometime in coming weeks.
To their surprise, *perhaps* related to unusually high winds, the system failed sooner than they thought it could.
The completed their improved design and are now installing it. (And they are counting their blessings that nobody was killed: they got lucky, that way.)
-t