I don't know the area there, but bear in mind that industrial plants and fuel depots do have dramatic accidents and explosions from time to time that have nothing to do with terrorism. Its just goes with the territory. In Houston we have numerous oil and chemical refineries, and at times we have had multiple instances in a single year, none of which were terrorism. So we'll see.
That's why I asked him if there was a refinery there. I seem to hear of refinery kabooms fairly often. Well, more often than one would think is normal, but not too many accidents for just a tank farm.
Maybe some driver went off the M1. Heck, we had a plane in Chicago go through a fence and kill someone the other day so I guess anything is possible.