I was told this was a true story about a town in Wisconsin. This town is mostly flat land and corn fields. There are some pretty deep woods off the highway that shelter a church, said to have been built in the late 1800s, but long abandoned.
At some point, teenagers and an old creepy man began performing Satanic rituals at the church. They made attempts to call creatures from Hell or inter-demensional demons.
Later, police found everyone dead at the church after they'd been missing for a couple days. Completely shredded and mutilated at the site. The general consensus is that they succeeded in their efforts, but were unable to control what they had summoned.
A social studies teacher I had in junior high claimed that this legend is well-known in the town, and that townsfolk know when driving near the church, you never stop your car. Whatever was released is still there, hunting at night.