That assumes, though, that the ship's crew was comprised of terrorists and they knew what was on board. It's just as possible that they are completely innocent, and even if it's a bomb, it was going to be delivered like any other cargo to someone who planned to use it at a later time.
There's also the possibility that this is just some components for a bomb, either full blow fission device, or "dirty bomb", not the entire bomb.
A quick look at the MSNBC story shows that the ship is a container ship. Thus a bomb could very easily have been in one of the containers, and the crew wouldn't have a clue.
Glad I don't live near a harbor, but then again the container could just as well have been loaded onto a truck bound for Denver, about as far from the Ocean as you can get.
I kind of forget, how did the middle eastern terrorists in Clancy's fictional "Sum of All Fears" get their device to into the country and to Denver? My copy is in a storage place in San Antonio, and I'm in Oklahoma City, so I can't just pull it off the shelf and check for myself.