CHIPPEWA FALLS, WIS. – A western Wisconsin pickup truck driver had been "huffing" chemical vapors shortly before he hit and killed three Girl Scouts and one of their parents as they picked up litter Saturday along a western Wisconsin highway, authorities said Monday.

Colten R. Treu, 21, of Chippewa Falls, appeared in court Monday and remains jailed on at least a dozen charges, including four counts of homicide by intoxicated use of a vehicle and four more charges related to fleeing the scene before he surrendered later Saturday.

"There's a deep sadness in this town," said Jim Woldhuis, pastor of Chippewa Valley Bible Church, where a mother and daughter killed in the incident were active members. "We can't make sense of such tragedies.

"I've heard the theological arguments, but that doesn't hit the average person who asks, 'Why?'

"It's a broken world. It's a broken world."

Also Monday, authorities released the identities of those killed in the crash about 11:40 a.m. along County Road P near the Hwy. 29 overpass in Lake Hallie, roughly 95 miles east of Minneapolis. Police identified the victims as Jayna S. Kelley, 9, and Autumn A. Helgeson, 10, both of Lake Hallie; and Haylee J. Hickle, 10, and her mother, Sara Jo Schneider, 32, both from Lafayette. Jayna and Autumn attended Halmstad School, and Haylee attended Southview School, a district spokeswoman said. Haylee and her mother both attended Chippewa Valley Bible Church.

A 10-year-old girl remains hospitalized in stable condition. Officials have yet to disclose her identity, but the mother's Facebook account identifies her as Madalyn Zwiefelhofer and includes a photo of the girl tending to her duties picking up litter. Dianne Zwiefelhofer said Monday that her daughter and family "need prayers at this time."

Two of the girls and Schneider were dead at the scene. Two other girls were taken by ground and air ambulances to a hospital, where one of them died later Saturday. Authorities have not released details about where each of the girls died. Madalyn was initially reported to be in critical condition and later listed in stable condition.

Treu was speeding north on County Road P in his pickup when it veered over the centerline and into a ditch where some of the fourth-graders and Schneider were collecting litter as part of an "Adopt-A-Highway" group of 12 walking along both sides of the road, according to police and witnesses.

District Attorney Wade Newell said during Monday's hearing that Treu and a passenger had bought dusting aerosol cleaner that morning at a nearby Walmart, and Treu "was somewhat out of it." Police said the pair told them they had been "huffing" chemical vapors from the cleaner.

The passenger noticed the pickup was drifting, started arguing with Treu and grabbed the steering wheel in hopes of correcting the vehicle's course, Newell continued.

However, the pickup continued into the ditch and hit the girls and Schneider, Newell said.

Treu attended Monday's hearing via closed-monitor video. Wearing a dark T-shirt and dark pants, he sat with his head down and his hands folded during the proceeding. His defense sought bail of $1,000, pointing out that Treu has lifelong roots in the area, is employed and is a father.

Newell argued for a high bail amount, noting that Treu has been "engaging in reckless behavior on a continuing basis." The judge set bail at the heftier sum — $250,000 in cash, with conditions.

Treu's criminal history in Wisconsin includes a drunken-driving conviction in Chippewa County after authorities measured his blood alcohol content in late 2014 as above the legal limit of 0.08 percent but less than 0.15 percent.

At the time of the fatal incident, Treu was on bail from a similar incident on Sept. 30 in nearby Rusk County, where he is charged with driving his employer's vehicle into a ditch while "heavily intoxicated."

Safety vests on

The Girl Scout group Saturday consisted of seven girls and five parents, and all were in the ditch and had on "highly visible" green safety vests, according to a police statement Monday.

After the crash, a sheriff's deputy "diligently tracked" vehicle fluids from the scene roughly 1¾ miles north to Treu's residence in Chippewa Falls, the statement read.

Law enforcement located the truck in the garage, but Treu and the passenger had already left the house.

Nearly five hours after the crash, Treu's mother brought him to police. His passenger surrendered to Eau Claire police Saturday afternoon.

The girls were members of Troop 3055. Counselors and therapy dogs were made available to students and staff when classes resumed Monday. A moment of silence was observed at the start of instruction at the high school.

Halmstad art teacher Robin Kelley is the mother of Jayna, one of the girls who died, district spokeswoman Michelle Golden said Monday. Robin Kelley was among those on the litter detail but was not hit, Golden said.

The incident took place in farm country just outside Chippewa Falls. On Monday, a utility crew was at work near the site of the deaths.

"I was surprised at how busy this road is," said William Garner, one of the workers. Garner suggested that perhaps community groups would be better off cleaning up bike paths and other less-traveled roadways.

"Leave the highways for the criminals," he said.

Funeral arrangements

Churches and funeral homes in Chippewa Falls have worked out staggered funeral arrangements on Wednesday and Thursday for Autumn, Haylee and Sara Schneider so that anyone who wants to attend all three visitations and all three funeral services can, Woldhuis said. Jayna's funeral is scheduled for Friday.

Sara Schneider's online obituary said she worked for Hewlett-Packard's facility in Chippewa Falls.

"Her favorite time spent with her children was everybody in their jammies snuggling in for a good movie," the obituary read. "Sara loved painting, making crafts with her daughter and sisters, and all the arts, volunteering for the Girl Scouts and in her church."

Daughter Haylee "loved crafting and painting with her mother," the girl's obituary read. "She shared a love of noodles with Parmesan cheese and butter with her mother. … She enjoyed participating in the Girl Scouts" and in church activities, the posting continued.

Residents of western Wisconsin are reeling from the impact of several recent tragedies. The area has seen the disappearance of 13-year-old Jayme Closs of Barron, Wis., and the killing of her parents. And on Monday came the shocking news that a 10-year-old girl from the Chippewa Falls area had been charged with first-degree homicide in the death of a 6-month-old boy.

"I always think Wisconsin is safe and protected from that big-city life," Golden said. "It just gets you. It puts you right there with your own family.

"Our faith leaders have been very helpful with this, and people have been wonderful. We definitely feel long arms around us of heartfelt sentiment.

"But right now, it's so raw for everyone."

Staff writer Erin Adler contributed to this report.