Police are trying to figure out what caused a man to veer into oncoming traffic and crash his rented minivan head-on into a mother on her way to baseball tournament with a car full of kids.

Pictures from Oregon State Police

Scene of three vehicle accident on Highway 26 east of Sandy that killed four people.

Both drivers were killed in the crash, along with a toddler and an 11-year-old boy. Additional people were injured and taken to area hospitals.

Reporter blog: A difficult story to cover

The head-on crash happened around 8:30 a.m. Saturday morning on Highway 26 at Cherryville Drive, just east of Sandy. Officials at the scene said that a rented Dodge van driven by Lewis Lambert, 68, of Gaston, was heading westbound on Hwy 26, crossed the center line and hit the minivan.

After impact, the van spun around and was struck by an eastbound Toyota Sequoia. Lambert was killed in the crash, police said.

Janene Brundege, 44, of North Portland, was also killed. Her 23-month-old daughter, Abigail Kay Brundege, was believed to be in a child safety seat but was ejected out of the the van and was killed. Another child, who was a family friend, Tyler Williams, was also killed in the crash.

The third child in the car, Janene's 11-year-old son, Quinton Brundege, survived and was transported to Legacy Emanuel Hospital with serious injuries. The two boys were youth baseball teammates with North Portland Junior Baseball and were enroute to the Welches area for a baseball tournament.

The third vehicle, a green Toyota Sequoia was also heading eastbound. The SUV had six adult occupants who were believed to suffer non life-threatening injuries. They were enroute to go rafting. The driver of the SUV, Mark McKell and his wife Heather McKell were taken to Oregon Health and Sciences University where they were treated and released.

Sequoia passengers Scott and Janee Russon were transported to Legacy Emanuel hospital where they were listed in good condition Sunday. Their passengers, David and Lidsey Liebert were transported to Oregon Health and Science University where they were listed in fair condition.

Highway 26 was closed until mid-afternoon on Saturday during the investigation.