Police in Maryland had to deal with a potential blast from the past after a resident discovered a live cannonball from the Civil War.

The Maryland State Fire Marshal said in a Facebook post that members of the bomb squad were dispatched to Frederick County on March 22 after the device was discovered by a homeowner.

“Bomb technicians conducted diagnostics and determined the fusing mechanism was still intact,” the fire marshal’s office said.

The homeowner received the cannonball from another family member who had earlier discovered it near the Monocacy National Battlefield. A bomb squad safely transported the cannonball to Beaver Creek Quarry in Hagerstown and conducted an emergency disposal, according to officials.

The fire marshal’s office said unexploded military ordnance has been found on the Chesapeake Bay shores due to the state’s long history of military testing. There are some instances where devices are found inland and still pose a danger to the public, according to the fire marshal.

“If you should uncover or are unsure if an unidentified object may be military ordnance, be safe rather than sorry. Stay away and call 911,” State Fire Marshal Brian S. Geraci said in a statement. “Marylanders need to be mindful that military ordnance, even vintage artifacts from previous conflicts, have the potential to explode.”