A Kansas girl who was reportedly riding on the back of her grandfather's motorcycle was killed in a hit-and-run.

According to a Douglas County Sheriff's Office news release, 9-year-old Brooklyn Brouhard was a passenger on a motorcycle driven by Barry Larson, 54.

The pair were driving along a Lawrence, Kan., roadway Sunday, when they were struck by a white Ford transit van, the release read.

Following the collision, witnesses told authorities the driver fled.

While waiting for first responders to arrive after the crash, two women, one of whom was a nurse, reportedly pulled over to help the injured pair, according to KMBC-TV.

"The nice lady that I just spoke to did life-saving measures on the child, but also said another female was there rubbing her back, you know, basically just trying to comfort her," Sheriff Jay Armbrister told reporters, per the outlet.

Despite the attempts of good Samaritans to save the 4th grader, Brooklyn succumbed to her injuries at the hospital, the sheriff's office said. Her grandfather sustained serious, but non-life-threatening injuries.

"We honestly believe that the driver knew that this had occurred and chose to leave the scene anyway. So that just makes it very, very difficult to kind of wrap your head around," Armbrister said. "It's even more than frustrating, it's infuriating."