The Minnesota State Patrol says a father and his toddler son were killed and two others injured after a two-car crash on Interstate 35 in Forest Lake.

The crash happened just before 11 a.m. Sunday. Investigators say a pickup traveling northbound on 35 lost control near Highway 8, crashed through the median and began to roll when it hit a Toyota Camry coming the opposite way.

They say a man and young boy in the Camry died. Their names have not been released.

The State Patrol says the driver of the pickup, 19-year-old Eric Sprouse of Wyoming, Minn. is in critical condition after being ejected from the truck. His passenger, 20-year-old Dustin Covey, also of Wyoming, received non-life threatening injuries.

Investigators are still trying to figure out what caused Sprouse to lose control of the pickup. They do not believe alcohol played a role, but say inattentive driving may be involved.

Traffic on southbound I-35 was blocked for a couple hours after the accident.