What’s beneath the Detroit River? What’s lurking down below? Magnet fishing reveals the hidden secrets and treasures that lie on the bottom. The images in the gallery below were taken by an underwater drone that was attached to a magnet and dredged over the river bed. What they reveal is fascinating. A saw blade, boat anchors, knives, cell phone parts, pliers, fishing bells, spark plugs, flip phone, and other items that just can’t be identified…