DALLAS — More than two years later, Bobbie Gilbert struggles to grasp her brother’s death. Her brother, Michael Wells, was on his way to work in Fort Worth during a deadly 2021 winter storm when cars began to skid on a two-lane tollway. Vehicles smashed together on the narrow, iced-over road, damming the interstate as traffic continued. He was stuck and stranded, his family says, when an 18…