Three people have died and two, including a six-month-old baby, have been seriously injured after an accident overnight on the M4 near Cardiff.
Police said the casualties were all from the Porthcawl area.
The incident happened at 2330 GMT on Monday. The westbound carriageway was closed throughout the night but has now reopened.
Officers are appealing for witnesses to the single-vehicle collision, involving a red Peugeot 406, or anyone who saw the car beforehand to contact the Roads Policing Unit on 101 or the independent charity Crimestoppers anonymously on 0800 555 111.
In particular, police would like to speak urgently to a couple who are thought to have stopped momentarily after the collision.