Law enforcement officials say three Girl Scouts and one woman collecting trash on the side of a western Wisconsin road have been killed in a hit-and-run crash.

The Minneapolis Star-Tribune reports the driver of the pickup that hit the group fled the scene but is now in police custody.

The driver of the pickup that hit the group, 21-year-old Colten Treu of nearby Chippewa Falls, Wis., fled the scene but later turned himself in, according to Sgt. Daniel Sokup of the Lake Hallie Police Department. A fourth girl who was struck by the pickup remained hospitalized in critical condition as of Saturday evening. The girls were picking up litter in a ditch along County Road P near the Hwy. 29 overpass about 11:40 a.m. when a black Ford F-150 pickup veered off the north-south road and hit the group, police said. The driver then sped off, according to multiple sources, leading Lake Hallie police and other agencies on an intensive hunt.

A fourth girl struck by the pickup was in critical condition Saturday evening. Chippewa County Sheriff’s Office wrote in a statement shared to its Facebook page:

This is a truly horrific incident. Our thoughts and prayers go out to the families, friends, fellow students, fellow scouts and everyone else impacted by this. Truly, as a community, this affects every one of us. Something very precious has been lost and nothing can bring it back. We grieve with you. With grief can come pain and anger for what has happened. Our focus and our energy needs to be with those impacted by this terrible event.

Lake Hallie police are leading the investigation.

The Associated Press contributed to this report.