In any event, once the fire is out, it will be relatively easy to determine the point of origin as well as the cause. Even in a very hot fire, the evidence of origin doesn't "burn up". We've even determined point of origin in residential structures that had nothing left but the concrete foundation and a few charred timbers.
I am always fascinated by the work that arson/fire investigators do. Just amazing work they do.
The CLTV report makes it sound as though the explosion was primary, but you're right...we have to wait for the investigation.
I'm confortably sitting here on the east coast, reading through, and I have to say your posts are absolutely fascinating.