Last weeks’ bomb blasts in Downtown Yakima left something behind. An on-scene coordinator for the Environmental Protection Agency says last week's explosives left visible droplets of mercury in two nearby parking lots and alleyways.

Multiple explosives went off near 11th Avenue and Chestnut around 10:30 Thursday night. The EPA says the City of Yakima put in a thick layer of asphalt over the worst spots to cap the mercury in place. The agency said it's good the spill was caught early because it minimizes the potential for it to become airborne.

"It's much cheaper and also more protective of human health to get it cleaned up immediately," said Kathy Parker with the EPA. "If you let it go, it tends to spread all over the place as people walk through it and cars drive through, gets in the air and people breathe it."

The EPA said the explosion area is now considered safe to be around.

Police said there are currently no suspects and no motive for creating the bombs. The case is still under investigation.