Colorado Springs Utilities now has an idea of what may have caused
Thursday's underground explosions.
They say fuel or fertilizer illegally dumped into sewers may have caused blasts that shot several manhole covers into the air.
Tests on a sewer line reveal some kind of solvent and wastewater lines have, now, been flushed to prevent further explosions.
They say they still don't know where the fuel or the fertilizer may have come from.
About 40 people were evacuated from their homes but, luckily, no one was injured.