An investigation is underway following a hit-and-run on Kauai that left two teenagers with critical injuries.  Just after midnight on Sunday, July 9, the Kauai Police Department arrested a man in his 20s after he turned himself in.  The man was arrested in connection to the hit-and-run on Poipu Road, where two visitors — a 13-year-old girl and a 15-year-old girl — were struck by a pickup truck while crossing the street in Poipu.