Complex sentence: Lightning struck the Ehingen Tower and when the doors of the prison were opened, thick smoke billowed out of the cell where Hohenleiter was held and Xaver Hohenleiter was found lying dead on his pallet, having been struck by lightning.
Split into simpler sentences: Lightning struck the Ehingen Tower and when the doors of the prison were opened, thick smoke billowed out of the cell where Hohenleiter was held. When the door of the cell was opened Xaver Hohenleiter was found lying dead on his pallet, having been struck by lightning.