Workers dredging in the Baltimore Harbor Monday afternoon discovered a cannonball that might date to the Civil War era off Hart-Miller Island near eastern Baltimore County, according to the Maryland state fire marshal's office.
The 25-pound ball was described as in "very good condition" and was still explosive, according to Deputy Chief Jason Mowbray.
Bomb experts with the state fire marshal's office rendered the ordnance safe, Mowbray said. He declined to elaborate on the procedure.
The fire marshal's office was called about 4 p.m. Monday after a private contractor disposing of dredged material on Hart-Miller Island discovered the cannonball in the muck being deposited.
Despite its age and having been buried, the cannonball still contained black powder and could have injured workers, Mowbray said.
Hart-Miller Island is a state park southeast of Rocky Point Park and Breezy Point Beach.
In November, workers dredging the Patapsco River near Fort McHenry in Baltimore found three 8-inch cannonballs, which dated to the Civil War.
State officials and historians called the age of the cannonballs perplexing because Baltimore saw no action in the Civil War. They surmised that the ordnance might have come from Fort McHenry and been used in Union exercises.