RIVERSIDE, California — A 19-year-old man has been arrested in connection with a fatal hit-and-run that claimed the life of a pregnant teenager late Sunday night, according to the Riverside Police Department. The incident occurred around 11:45 p.m. in the University neighborhood.Officers responded to the 1500 block of Gregg Place and found the victim, who had been struck by a vehicle that fled the scene. She was transported to a local hospital, where she later died. Medical staff delivered her baby, who remains in critical condition, stated the department.The suspect, identified as Isaac BlackhorseGarcia of Moreno Valley, was located and taken into custody. Investigators determined that BlackhorseGarcia had been in a sexual relationship with the victim’s teenage sister……