Several years ago A church in my community burned. Build in the late 1800, heavy timber. Fire supposedly stared in the basement, and quickly made it up the wall cavity was a straight shot to the roof with massive old wooden beams everywhere. At that point it was a surround and drown operation and try to save the newer attached additions.
As with most church fires, the original building was a total loss. They are usually old, very unlikely to be sprinkled and unless caught and extinguished with a few minutes no FD can throw enough water at it to save.
I worked in a building (3 stories) that had been built in 1870. It had a tremendous amount of large wood beams, plus wood floors, etc...
There was no question in my mind that if it caught, there would no stopping it.