Incompetence and poor maintenance resulting in a major accident is still at least as good of an explanation as sabotage.
It certainly is still a valid explanation, but as I mentioned in an earlier post here, I would be more inclined to believe poor maintenance if the simultaneous explosions were within the same manifold system. At any rate, the United States already officially stated that it was sabotage by the ruskies, so if you don't believe that, you're an unpatriotic and disloyal domestic terrorist.