That probably means it was a serious explosive. Black powder makes lots of smoke. TNT does not, nor does stuff like C-4. Not that I'm saying it was either of those, but generally speaking the high detonation velocity stuff doesn't produce all the much smoke. Hollyweird has conditioned us to believe all explosions look like... well like a 757 hitting the WTC.
Interesting. I am guessing the higher explosives burn at such a fast rate they don't have time to produce a lot of smoke. Would that be correct?
Just worked my way through to your post. I agree.