Two children were among the four people killed late Saturday in a head-on collision on a northern California freeway, police said. The California Highway Patrol said a minivan and a Toyota Prius crashed when the Prius apparently veered into oncoming traffic on Highway 50 near Placerville. Two adults and a child in the Prius were killed as was a 4-year-old passenger in the minivan, UPI quoted officers as saying. A set of 1-year-old twins in the van and a 10-year-old in the Prius were among the injured.