Deputies said the man who found the grenade took it to the Miami County Sheriff's Department on West Main Street in Troy just before 7:30 p.m. Monday.

The bomb squad from the Dayton Police Department was then called to the scene.

The swimmer eventually left the device on the plaza between the Miami County Safety Building and the Miami County Courthouse outside of the Sheriff's office.

Inmates in the county jail were all moved to the east side of the jail and several blocks in all directions were roped off.

The grenade was described as a pineapple hand grenade, dating back to World War I and II. According to deputies, the grenade appeared to be live and had been tampered with at both ends.

The grenade was loaded into a sand-filled dump truck from the Miami County Highway Department and transported several miles to the Troy Police Department shooting range, which is located off Dye Mill Road and destroyed.

The explosion, shortly before 1:30 a.m. Tuesday, could be heard for miles.

Sheriff's detectives are looking further into how and where the grenade was found, and where it may have come from.