The blast happened during a cleanup at the facility that produces illumination mortars the military uses to give light to soldiers, Peske said. Employees follow certain procedures to clean up any loose chemical dust at the beginning or end of a production run.
Peske said he doesn't know what chemicals are used, but that they are part of the production of the illuminating candles for the mortars.
The facility has been shut down as Crane looks into the cause of the explosion.
"Safety of all our employees remains our primary concern, so we will do everything possible through the investigation to ensure that a future accident like this won't happen," Peske said.