Investigators say a Texas man, not his 13-year-old son, was driving the pickup truck that crossed into the oncoming lane and struck a van carrying New Mexico college golfers, killing nine people, and that he had methamphetamine in his system.

Authorities are trying to determine why a pickup truck crossed into the opposite lane on a darkened, two-lane West Texas highway before colliding head-on with a van, killing nine people including six New Mexico college students and a golf coach.