The Golden Gate Bridge parallels the San Andreas fault and is designed to withstand large earthquakes. Also the bridge was designed and built when it was still a possibility that the continental United States could be attacked by a foreign power, i.e. Pearl Harbor. At the time of the bridge's construction there were huge gun implacements setup around the bridge to fire upon attacking battle ships (those huge guns are now long gone). I suspect (don't know) that the bridge was designed to take a couple hits from a battle ship (16-18 inch shells) and still stand. Therefore I think any terrorist short of a nuke would be wasting his time attacking the bridge. Of course the road work of the bridge could be damaged if a truck bomb went off. However that could be repaired in a few days/weeks.

Gary