Just don't see the connection between a senator from Minneapolis and a bridge collapsing as conspiratorial.
Nor, do I see the pictures you posted as evidence that a BOMB went off.
The only conspiracy I see here is that the STATES do not receive enough funding to maintain and repair the bridges that are reported as structurally deficient before they collapse!
I guess we just have to wait for the other 7,000 to collapse during rush hour traffic before they receive funding to rebuild them.
Perhaps their motto is:
"If it ain't broken, don't fix it. Wait for it to collapse."
Could you live without conspiracy theories? :-)