Chances are, skipping the second leg will count you as no-show and the rest of the itinerary will be cancelled. You can either call the airline and reticket, paying the fees, or book a new one-way ticket from DFW-BDL which may be cheaper. The "chances" part of that depends on the type of ticket you bought; some of the more expensive, unrestricted tickets will let you make this change at no cost, but most regular tickets would not have this flexibility and you'll be cancelled by no-showing.