A farmers coop elevator in the town of Woolstock is off-limits after an explosion Monday morning that may have been caused by grain dust as railroad grain cars were being loaded. Bruce Rholl is fire chief in the Wright County town. He says the state fire marshal and engineers are at the scene, and he says they’re going to keep that area off-limits. After the explosion Monday, about two-dozen people had to leave their homes as fire officials cordoned off a couple of blocks to keep people away from falling debris and the risk of more explosions.