A 28-year-old woman has died after a car she was travelling in collided with a tree in Merthyr Tydfil.
The incident happened on the Pontsticill to Paint road, by the Pant cemetery, and involved a green Honda Civic car.
A 36-year-old local man is being detained in hospital with serious injuries.
Her family have been told and are receiving support from a police family liaison officer.
South Wales Police are appealing to anyone who saw the collision, anyone who saw the car being driven before it crashed or who may have seen a man walking along that section of road at about 1.30am this morning.