High powered magnet fishing leads to strange catch

With a pair of 68 lb heavy duty magnets, this amateur salvager has created a magnificent trolling rig. It may not be as exciting as pulling in a large mouth bass, but he still makes a few facinating finds among all the garbage. In just a few hours he pulls out some rail spikes, a Zippo lighter, and a complete 8-track tape deck from the river. How did that even get there in the first place?