A Ham Lake teenager driving a minivan ran a stop sign north of the Twin Cities and struck a car broadside, killing the smaller vehicle's driver and critically injuring two of her children, authorities said Monday.

The crash happened southeast of Isanti County shortly after 6:15 p.m. Sunday at Durant Street and 269th Avenue, according to the State Patrol.

Killed was Christin Birkholz, 30, of Isanti, the patrol said.

A minivan with 16-year-old Melody Lewis behind the wheel was heading south on Durant when she went through the stop sign at 269th and broadsided Birkholz's westbound car.

The car, with Birkholz and her three children inside, rolled into the ditch and came to rest on its roof. Birkholz was not wearing her seat belt and was partly thrown from the vehicle.

Her sons, Logan, 10, and Mason, 1, were taken to Hennepin County Medical Center in Minneapolis and were in serious condition Monday. Bailey, 4, was treated for minor injuries at Cambridge Medical Center and released. All of the children were wearing restraint devices.

Melody Lewis, her 47-year-old mother, Laurie Lewis, and 14-year-old sister Bethany Lewis, were all treated for slight injuries and then released from Cambridge Medical Center. All were wearing seat belts.