It was the truck bomb, on the road.
A water-level attack MIGHT have taken out a pier, at water level, (MIGHT, depending on amount of explosive, configuration, placement, etc.), but the damage clearly was from above, to the roadway, and the side-flash of the elevated explosion ignited the tanker cars on the adjoining RR bridge.
In my younger days as a UDT/SEAL, I have been on the beach and in the water with small groups that, combined, blew up tons and tons of C-4 and TNT, any way you can imagine. Including making our own shaped charges, platter charges, etc. From little one-pound devices to a ton at a time. Often using high explosives in industrial quantities as a raw material, for custom applications (in training only.)
I just mention the above as bona fides. I know what I’m talking about.
A water-level attack MIGHT have taken out a pier, at water level, (MIGHT, depending on amount of explosive, configuration, placement, etc.), but the damage clearly was from above, to the roadway, and the side-flash of the elevated explosion ignited the tanker cars on the adjoining RR bridge. You can believe whatever you want, and opine whatever you want. From the photo, the bridge decking was forced up from the force of the explosion. Directly under the explosion, the bridge decking was damaged from the heat of the blast, resulting in its failure. The photo also shows that the decking was pulled up and out from a pier three piers away from the blast. Sorry, but a truck bomb can't do that. It's simple physics because it is too far from the blast itself. The explosion was obviously from below. Secondary explosions or combustion caused the scorch marks on the bridge. The heat of the blast alone could have ignited the rail car tankers.
