OUCH! I sure hope they have insurance and that it was not arson!!
If it had been arson, the lower half of the building is what would have burned. This was lightning, plain and simple. There are lots of fires caused by lightning strikes every year, they just don't make the news.
I should have said what burned first was what was struck by lightning. Looks like the steeple was hit, and is mostly gone, while the rest is still fully engulfed. Also, there was a storm going on at the time, with lightning striking, and a witness in the story mentioned hearing the pop when it hit.