Wow big fire. I'm surprised it didn't make a bigger hole in the building. Looks like it only effected parts of two floors.
If it was a four- or six-seater general aviation aircraft, you're talking about a maximum of maybe 3500 pounds weight, moving at maybe 100-120 mph. A nasty impact, but not something that would do massive structural damage to a building like that. Basically, think a fast-moving car with lightweight wings that'll crumple on impact.
}:-)4