Where does oil come from? A lot from Muslim Mideast. Who are we at war with? Muslim Mideast. Who has opportunity to rig oil tankers with detonation? Mideast Muslims. I am very suspicious of petroleum explosions in America no matter what Homeland Insecurity announces.
Actually, the US doesn't get that much of it's oil from the Middle East (that mostly goes to Europe and Asia). We get much of our oil from Venezuela, Mexico and Nigeria, especially in the eastern half of the US. While Nigeria has it's Muslim/Christian/Pagan conflicts, that's mostly an internal struggle (for now). Theft and corruption is probably a bigger problem for keeping Nigerian oil flowing.
Nope, this isn't terrorism; the Coast Guard security checks are pretty good about this. There would have been a boarding party while the ship was out at harbor before docking and an inspection. This was an accident caused by bad weather.