Train services between Carmarthen and Swansea have resumed after being cancelled due to a broken track.
Rail services were stopped after the line was damaged between Ferryside and Kidwelly in Carmarthenshire on Monday.
Network Rail said the "extensive damage" was caused to about 50 miles of track following a serious fault on a freight train.
Services restarted on Wednesday following repairs.
Bill Kelly, chief operating officer for Network Rail, thanked passengers for their patience during the disruption.