It’s unclear what caused an off road vehicle crash that killed a Tehama County man Saturday morning. 76-year-old Michael LaGrande and a 10-year-old Chico girl were on a new Honda SX 1000 side-by-side tooling around a private ranch off Newville Road south of Round Valley Road. The CHP says it may have been a medical condition that caused LaGrande to speed up to 40 miles an hour and then make a sudden turn to the right. That flipped the vehicle onto its left side, killing LaGrande. The girl was not injured. The CHP does not suspect drugs or alcohol.