There have been Oil terminal explosions in Hemel Hempstead/St Albans oil terminals, some witnesses claim they saw a plane go down just before the explosion, but it hasn't been proven..hmm hope it's not another terroist attack.
There have been casualties, I'm not sure about deaths, but some places nearby have been evacuated, and people heard the explosion from upto 30 miles away.
I saw it on the news, and there is a massive cloud of bellowing black smoke, and huge flames, apparently 60 ft high, and the fire is too fierce to fight.