Two vintage hand grenades created something of an adrenaline rush when they were discovered Thursday evening by staff of a storage facility cleaning out an abandoned storage unit. 

Security Public Storage staffers were quick to call 911 when they spotted the suspected explosive devices in a see-through tub near the front gate of their facility at Lathrop Road and Crestwood Avenue. Two Manteca Police officers assigned to the county bomb squad, along with a Stockton Police officer/bomb technician, responded to the scene within half an hour.

Bomb squad commander Mike Keener donned the anti-flak suit and protective head gear and entered the storage unit where he located the grenades and placed them in a padded, black anti-explosion case and carried it out to their team’s truck parked at the curb. A fire department engine stood by in case of an unexpected explosion. The team transported the grenades to the old police target range off of South McKinley Avenue where they dug a two foot hole, placed the devices in the hole and blew them up with a secondary charge.

Officer Keener said following their detonation of the device it was undetermined whether the grenades and their attached firing pins were the real thing as pictures lead them to believe them to be.

The Mark 2 defensive hand grenade is a fragmentation device used by the U.S. armed forces during World War II and in later conflicts including Korea and the Vietnam War. It was first introduced in 1918, replacing the failed Mark 1 of 1917 and was standardized in 1920. It was phased out gradually in service beginning with the Korean Conflict.

The grenade was manufactured with grooves in the cast iron body, falsely believed to aid fragmentation – only providing a better grip when thrown. This gave it the appearance of a pineapple that gave it the nickname of the “iron pineapple.” It was also known as the “frag” grenade since it was the only fragmentation grenade used by American forces. 

It possessed a percussion cap and a time fuse with a five second delay.