(PORT HURON) -- Authorities say an inert practice military bomb was found by a scuba diver in Lake St. Clair Monday. Port Huron resident, Robert Grattan, retrieved the device from the bottom of the lake and took it to the police department. Port Huron Police requested the assistance of the Michigan State Police bomb squad and blocked off a street near the Port Huron Municipal Office Center. The building was not evacuated. MSP bomb squad members examined the device and found it to be inert. The device was described as a vintage military practice ordinance or practice bomb, which was never used. It was turned back over to Grattan. Residents are reminded to not handle such devices, as they can be dangerous and could explode unexpectedly.