A young Roseville man and his father were killed when their car collided head-on with a semitrailer truck around noon Tuesday in southern Dakota County, authorities said.

The State Patrol said that the 18-year-old was behind the wheel, northbound on Hwy. 56 northeast of Randolph, when the car crossed the center line, hitting the southbound semi rig.

The names of the driver and his 53-year-old father, who the patrol said lived in South St. Paul, are to be released Wednesday.

The truck driver, Melvin Doffing, 59, of Spring Valley, Wis., was uninjured.

Alcohol was not believed to be a factor, the patrol said. All three men were wearing seat belts.

JOY POWELL