On July 1, 33-year-old David Olson started a little demo on the back steps of his house; he wanted to build a new deck. The project took a turn when Olson, who lives in Norton Shores, Michigan, uncovered an odd black sphere buried behind the cinder blocks. He found a bowling ball and, at first, he didn't think much of it, but then he found about 157 more.
According to the Detroit Free Press, Olson thought the balls were just used as fill, which he was fine with since they were easier to move than your typical boulder, but Olson wondered where they came from.
He reached out to bowling ball manufacturer Brunswick Bowling Products. Olson has three young kids and wanted to make sure that the balls weren't toxic. The company traced the balls back to the 1950s.
Up until 2006, Brunswick manufactured balls, pins and other bowling equipment in Muskegon, Michigan, which is a little more than five miles north of Olson's home in Norton Shores. Olson, who has chronicled his journey on Facebook, was recently contacted by former Brunswick employees who said that former workers used to take scrap bowling balls and use them as cheap fill. As you can see from some of the photos Olson posted, lines were carved into the scrap parts.