Appeal for witnesses following Tonna crash
South Wales Police is continuing to appeal for witnesses after a collision which happened at around 3.30am on the 29th December 2015.
Police have arrested a 20-year-old on suspicion of causing serious injury by dangerous driving.
The incident involving a single car happened on the B4434 Neath Road between Tonna and Resolven.
The road was closed while collision investigation work was carried out.
Four casualties were taken to Morriston Hospital in Swansea.
A 21-year-old man remains at Morriston with non-life threatening injuries and a 17-year-old girl and a 20-year-old man were released from hospital yesterday.
A 15-year-old girl was transferred to the Heath Hospital in Cardiff and remains in a serious but stable condition.