In 1646 , lightning hit the gunpowder tower of the castle of Bredevoort , causing an explosion that destroyed the castle and the town , killing Lord Haersolte of Bredevoort and his family , as well as others . In 1646 , lightning hit the gunpowder tower of the castle , causing an explosion that destroyed parts of the castle and the town , killing Lord Haersolte of Bredevoort and his family , as well as others .