A 6-year-old Rapid City boy died Sunday, the third victim of a one-vehicle accident on Interstate 90 near Sturgis that claimed the lives of a Sturgis man and child and injured two other children.

Tyson Lewis, 6, of Rapid City died Sunday morning of injuries sustained in the crash that occurred shortly after 7:15 p.m. Saturday east of Sturgis, according to the South Dakota Highway Patrol.

The driver, Brian F. Jackson, 42, of Sturgis died at the scene. Braden Osborne, 8, of Sturgis died of his injuries later Saturday evening.

The condition of the two other passengers, Zavan Osborne, 6, and Dakarai Osborne, 3, both of Sturgis, was not immediately known Sunday.

All sustained life-threatening injuries, according to a news release.

According to investigators, the 2003 Pontiac Montana minivan was traveling west on I-90 when the driver lost control and drifted into the median.

The car then struck the eastbound-lane bridge at Exit 34, fell onto the service road below and caught fire.

Passers-by pulled the four children from the vehicle before it was engulfed in flames.

All five occupants were wearing seat belts or sitting in child safety seats, according to the release.

As of Sunday afternoon, it was still not known why the van entered the median or if alcohol was a factor in the crash.

The Highway Patrol could not confirm what the occupants' relationship was.