Something else just occurred to me. If - IF - this were not an accident, early Sunday AM when it's still dark, and there were not that many workers on duty, would be an ideal time to sabotage and open some valves to cause a leak. And how hard would it be to leave some timed device to cause a spark, or have a buddy a little distance away shoot something into the cloud of leaked gas?
And would there be any evidence? I doubt it.
Perhaps a Muslim or two on the janitorial staff?
A sleeper planted a long time ago so as to gain everyones trust for when the right moment came.....12/11.
I still have not seen or heard anything yet to convince me this is just an accident.