That road is black topped. black top is a bi product of petroleum, so it will burn.
Once it begins to burn it is going to ruin the structural integrity of the bridge. A bridge can collapse from the right weakness in the right spot, but in this cause the whole thing was burning so it became one giant weak spot.
On the other hand twin towers had like 500,000 yard of hardened concrete with a massive amount of 200,000 tons of steel beams creating its structure.
The towers also had integrity based on vertical strength while the bridge was based on horizontal strength. It's hard to knock down a tower than it is a bridge due to how they are designed. Something horizontal like a bridge will collapse easier because it has a weaker integrity due to only having supports instead of a solid base under the whole thing.
I'm not arguing a conspiracy theory, I'm just arguing your comparison is very flawed and inaccurate. You aren't comparing apples to apples.