Dallas Area Rapid Transit says operations are returning to normal after all rail lines experienced delays Monday morning due to a mechanical issue with a train. At about 7:20 a.m., DART said all rail lines were experiencing delays due to a mechanical problem with a train near the Pearl/Arts Distr ict Station. About an hour later, DART said they had one cart out of service due to mechanical issues and that one cart remained in service. DART said shuttle buses are operating for riders and that all other services have resumed normal operations. DART did not say what caused the mechanical issue. Check back and refresh this page for the latest update. As developments unfold, elements of this story may change. ...read more read less