[Highland Park] Does anybody know what that smell was this morning?

There was a strange, industrial/smokey/smoggy smell wafting through my bedroom window this morning. I've smelled it before, but don't know what it is. I live near Jackson and Sheridan, but on several occasions I've gone jogging through the smell and found that it doesn't start to fade until I get up into the park near the reservoir at the top of the hill. Does anybody know what that smell is? Curiously yours, Mark markedixon@gmail.com