South Wales Police is appealing for witnesses.
It's after a serious collision on the M4 westbound between junctions 37 at Pyle and 38 at Margam at 2.58pm on Tuesday, June 12.
The collision involved a single motor vehicle, namely a grey BMW X5. As a result of the collision, the 28 year old female passenger sustained fatal injuries, and sadly passed away at scene. Her family is currently being supported by specially trained officers.
The 31 year old male driver of the vehicle, was conveyed to the University Hospital of Wales in Cardiff, by air ambulance, where his condition is described as serious and life threatening.
The eastbound carriageway of the M4 was closed near the scene for a short period of time to allow the air ambulance to land. The westbound carriageway remained closed for a number of hours, to allow investigative and recovery work to be completed. It has now fully reopened.
The police would like to thank the communities affected for their patience and understanding during this time.
South Wales Police is appealing for anyone who witnessed the collision, or the manner in which the vehicle was being driven prior to it, or who has any dashcam footage, to contact the Serious Collision Investigation Unit on 101, quoting reference *212882.