Bit of an update,
I took a look on
the church's website and found that it specifically says that the church was made of Brick and Concrete.
I can see the old exterior brick walls still standing. Based on the description of the construction of the church, the floor would have been poured concrete (which is in keeping with other churches constructed in the same time period).
That means that only the roof was made of wood. Which would make sense because wood is light and could be used to form trusses and span the nave.
Some photos of the interior from the church's website can be seen
here.
And more about the history of the building
here.
You can see in the above photo the use of spot lighting to illuminate the dome. You've got up lighting, down lighting and at different levels.
Now those lights on the left and right look like old school incandescent spot lights which would draw a fair bit of electricity and would generate heat. But the thing was, I doubt those lights would have been left on in the night. Any of them. That means no electrical current in the wires feeding the lights and no heat from the bulbs. It is possible that there was some sort of smoldering fire that occurred friday evening and took time to spread, but I have my doubts.
You can see from this photo and the photos below that plaster was applied directly to the brick walls. And it's still intact. Those brick walls are most likely able to be saved. That fire went straight up.
You can also see what appears to be wooden trusses with timber top chords and bottom chords and timber diagonal compression members. You can also see vertical steel tension rods (with a nut on the top of the top chord) running vertically down through the top chord and down and right trough the bottom chord to suspend the ceiling structure which may be concrete. (All of this is real hard to discern from these photos, but I don't see any rivets and there are lots of timbers laying on the floor.)
So this place had a suspended concrete ceiling, maybe ???
So how the fuck did it catch on fire?
Concrete floors, brick walls with plaster. And what appears to be a concrete ceiling. None of those elements burn.
If I'm correct, that means that the fire could only have started in the roof structure, above the concrete ceiling. And looking at the above photo, the truss in the foreground is far blacker than the truss in the background. and everything is destroyed in area which would have been above the alter.
Begs the question how.