Police in South Wales detained an 18-year-old on Monday for a fatal collision. Officers say a car plowed into a rider on a busy street near Newport. The victim lost life on site. The driver left the car close by, came back, and then fled. A man in the car was taken to hospital carrying injuries. Cops also detained another man related to a caravan fatality. They let him go but laid down strict rules. He is required to stay home and check in each week.