QUENEMO ? A man apparently suffered a heart attack when his van crashed head-on into another vehicle last week, killing five people, authorities said Monday.

The Kansas Highway Patrol had been trying since Friday’s accident to determine why Charles Campbell’s van crossed the center line of Kansas 268 in Osage County, about 35 miles south of Topeka, and struck another van.

Troopers said Campbell, 63, had been driving about 65 mph and left no skid marks.

Dr. Donald Pojman, deputy coroner in Shawnee County, said Monday there was “a strong indication Mr. Campbell lost control of the vehicle because he was suffering from a heart attack.”

The crash killed Campbell, of Wellsville, and his two passengers – Ramona Ball, 56, and her grandson, Elijah Ball, 1, both of Ottawa.

The driver of the other van, Rebekah Davidson, 35, of Quenemo, and her daughter, Nora, 2, also died. Davidson’s 5-year-old son, Abraham, survived with nonlife-threatening injuries.

The National Transportation Safety Board also is investigating.