Dania Beach – Sheriff's investigators say a man fatally shot his 1-year-old daughter and injured his 7-year-old son before killing himself during an argument with the children's mother along a South Florida road.The shooting happened about 01:30 on Wednesday in Dania Beach, which is just south of Fort Lauderdale.Broward Sheriff's spokesperson Gina Carter tells local news outlets the family was traveling in their vehicle. She says the mother got out of the car, trying to get to a relative's home for help.While she was inside, she heard gunshots. Carter says 32-year-old Timothy Hollis and Kalila Hollis were dead at the scene. Timothy Hollis jnr was taken to a hospital with critical injuries.Carter says investigators don't know what sparked the argument. The mother's name hasn't been released.