MILWAUKEE, Wis. -- Police are investigating after a garbage truck explosion injured a sanitation worker.

The blast is blamed on improperly disposed oxygen tanks.

The oxygen tank exploded as it was being picked up by a garbage truck in Milwaukee, Wisconsin.

Two men were behind the truck, preparing to add more trash when it happened.

Shrapnel hit one of the workers in the eye.

Luckily, he was wearing safety goggles and only suffered minor injuries.

Similar incidents have happened across the country.

Oxygen tanks should either be returned to a medical supplier or dropped off at a household hazardous waste facility.