Right. I am not really thinking of designing pillars that are impossible to knock over. I am thinking of alternative bridge designs where a higher percentage of the total bridge stays up when one pillar is taken out.

On this bridge, the main section of the bridge is supported by four spaced pillars, making three main spans there. One of the middle two towers was hit, so this should affect two of the three spans. But it took down all three of them. A span that was supported on both sides by intact towers still came down. That is what I find most surprising here.