WILLIAMSTOWN, Vermont – Fire crews in Williamstown say a smoke alarm warned a homeowner about a bag of wood pellets that almost spontaneously combusted. The Williamstown Fire Department was called to a home on Falls Bridge Road for a chirping carbon monoxide detector. After struggling to find the source of the odorless gas, they noticed a stack of wood pellet bags was heating up. Like wet stacked hay, the bagged wood pellets in the bags began to oxidize and heated up to 125 degrees. So officials are reminding people to store them safely and check their smoke alarms. “The best thing if you do store them inside is to make sure you have a working smoke detector or CO detector to give that quick awareness that something isn’t right,” Williamstown Fire Chief William Graham said.