'Smoke' in the Bible

When the men of Ai turned back and looked, behold, the smoke of the city ascended to the sky, and they had no place to flee this way or that, for the people who had been fleeing to the wilderness turned against the pursuers.

When Joshua and all Israel saw that the men in ambush had captured the city and that the smoke of the city ascended, they turned back and slew the men of Ai.