Colton Treu, 21, of Chippewa Falls, Wisconsin is charged in the crash that killed three Girl Scouts and one volunteer while they were picking trash on the side of the road.
The victims were struck Saturday morning while picking up trash along a rural road in Lake Hallie, 90 miles (145 kilometers) east of Minneapolis and just south of Chippewa Falls.
The surviving girl was hospitalized in Rochester in critical condition.
The vehicle then lurched back onto the road and sped off, according to police, leaving behind a scene of horror.
Two of them and the adult died at the scene, while the third girl died in hospital.
The Chippewa Falls Police Department expressed its condolences to the victims' families and fellow scouts, describing the events as a "truly horrific incident".
Jayna Kelley, 9; Autum Helgeson, 10; Haylee Hickle, 10, and her mother, Sara Jo Schneider, 32, were all killed when they were hit by a vehicle while picking up trash along a Wisconsin county highway shortly before noon Saturday, said Lake Hallie police.
It's understood the children had adopted the country road and had performed the community service before.
The Girl Scouts were all wearing bright safety vests and were accompanied by several adults.
A bond hearing for Colten Treu, 21, of Chippewa Falls will be held at 10 a.m. Monday in Chippewa County District Court.
Girl Scouts sing as hundreds of community members turn out in the rain Sunday evening, November 4, 2018, for a candlelight vigil at Halmstad Elementary School in Chippewa Falls, Wis.
"We're going through a storm as girl scouts and as a community", said Chippewa Falls mother and former Girl Scout, Tricia Voigt.
A candlelight vigil was held for the victims at Halmstead Elementary School, where two of the deceased girls attended, on Sunday night.
The driver fled the area, but later turned himself in.
Chippewa Falls School District Superintendent Heidi Eliopoulos sent a message to parents saying counselors, faith leaders and trained school staff would be available Monday at two elementary schools. One of the girls attended Southview.
The Lake Hallie Police Department extends it's deepest sympathies to the families involved.
WEAU 13 News plans to bring you that news conference live on air, on our website, and on our Facebook page.
This is an ongoing investigation.
Eliopoulos confirmed another girl is in critical condition. The other was taken to the hospital by ambulance. Striking vehicle is believed to be a black or dark grey Ford F-150 '04-'06 with heavy front end damage and missing both side view mirrors.
Officials say the crash happened at 11:41AM on County P at the 29 overpass near Weber Field.
Sergeant Daniel Sokup of the Lake Hallie Police said the stretch of road had no blind spots, with the crash occurring just before an incline in the road.
Anyone with information on the crash is asked to contact the Chippewa County Communications Center.