Yes, it is obvious. I thought of that and posted on it yesterday.
Although a PE, I’m not that kind of an engineer (electrical/electronic, actually). But, I can think.
Also, if you look at the bridge section, all you see is shattered concrete and the occasional reinforcing or tensioning rods. There is no substantial steel in the base section, which is what was supported at the ends and what broke.
In contrast, the superstructure and roof assembly is massively trussed, as it should be if it was planned to be bearing the load through tensioned cable stays. But, if the cable stays aren’t in place, it’s just so much more dead weight!
I wonder who was in charge of the assembly. Blaming the workers, undocumented or legal, is besides the point. Who gave the order to pin the bridge up by its ends without the central tower even being built, let alone attached by the staying cables? There has to be an assembly plan for this tinker toy!
The construction process here seems highly questionable.
If the bridge section failed at one end, then it was probably a shear failure. For a structure like that one, the maximum shear force (in simple terms, the force of gravity acting downward, and being resisted by the bridge support points) occurs right at the supports.
If the bridge section failed in the middle, then it would likely be a bending failure. For this bridge section, the maximum bending force occurs at the furthest distance from the support (in this case, the midpoint of two support points).
I am not a licensed engineer either. However, from what I remember from Statics and Mechanics, concrete has little to no tensile strength. It is the steel rebar and steel I beams inside the concrete that keep it from collapsing under it own weight.
I would think that the engineering firm would have been onsite when this was set into its final resting place. Without the center pillar and steel cables the concrete must have literally collapsed under its own weight.
Bottom run of the concrete cantilever suffered a cable tension loss?