Local firefighters responded to the state Department of Fire Services office in Stow after a Concord resident dropped off an unexploded WWII-era grenade on Friday, prompting fire officials to remind residents not to do that. The resident walked into the lobby of the Sudbury Road DFS office Friday afternoon, saying they had the grenade in their trunk. The state police bomb squad and Stow firefighters responded to inspect the device. State police determined that the device was inert and was likely a training grenade. "I would like to remind all residents to call 911 immediately if you find something suspicious or that resembles any kind of military ordinance," Stow Fire Chief John Paul Benoit said. "Do not attempt to move or handle any potential explosive. Leave the area and let first responders handle the situation professionally."