GRAND RAPIDS, MI -- A magnet fisherman pulled a World War I mortar from the Grand River and police later determined it should be blown up for safety reasons.

Joseph Alexander was fishing near the Sixth Street bridge about 3 p.m. Tuesday, Nov. 26 when he latched onto the device.

“When I first pulled it out of the water, I thought ‘That’s a grenade,’” he said Tuesday.

Alexander, later thinking it may not be a grenade, took the item to his Westside Grand Rapids home and posted a picture of it on Facebook.

He soon received several comments telling him it was, in fact, a mortar or grenade. He then called police and officers took the device.

“I really wanted to keep it, but I realize it could be dangerous,” he said.

Alexander said he’s been magnet fishing about a month and, so far, has pulled about 2,000 pounds of metal from the Grand River. He sells some for scrap.

So far, the mortar is the most interesting item he’s found.