PENDLETON, Ore. -- A "cumulative failure" at a state-run psychiatric hospital contributed to the death of a teenager struck and killed by a sport utility vehicle on Interstate 84, a state investigator determined.

Heather Williams, 18, of Veneta died Dec. 13 after jumping from a moving Department of Human Services van. She was a patient at the Blue Mountain Recovery Center in Pendleton.

In a report obtained this week by the East Oregonian newspaper, James Myrick-Duckett, investigator for the Department of Human Service's Office of Investigations and Training, found no individual was responsible for neglecting Williams.

He wrote that the neglect was a "cumulative failure between management, programs, policies and direct care staff to appropriately protect (Williams), which ultimately contributed to her death."

Williams had jumped from a moving Blue Mountain Recovery Center van earlier in 2007, and the staff knew about that incident. The investigator said witnesses and treatment team members "recognized and discussed the need to ensure (Williams') safety during transport."

Myrick-Duckett also found staff didn't know how to properly secure the van with child safety locks, and the center hadn't provided training.

One witness said Williams wasn't suicidal but was so impulsive and had such a need for medical attention, she was going to continue that behavior until she "did something very debilitating" to herself.

Kerry Kelly, Blue Mountain's superintendent, said the death was "a very unfortunate accident" and the center made immediate changes to its travel policy.

Before any client goes anywhere, the driver thoroughly checks the vehicle, including the safety locks, Kelly said. Once the client is inside the vehicle, the driver checks the safety locks again.

Kelly said no employees were disciplined, but all got training.

"The employees needed to be educated to do their jobs safely, and that's what we've done," Kelly said. "We put quite few checks in place to make sure nothing like this happens again."