A western Wisconsin woman was chatting on social media while driving just before a car crash near Prescott, Wis., that killed three young children in December 2013, police said.

Kari J. Milberg, 34, faces three counts of homicide by negligent operation of a vehicle and one count of reckless driving after police say she was active on Facebook while behind the wheel. Cellphone records show that Milberg was sending and receiving Facebook messages until two minutes before the crash, said Pierce County investigators.

Police believe distracted driving was a significant contributing factor in the incident.

Milberg's SUV spun out of control and slid into the path of an oncoming truck on Dec. 12, 2013. Her 11-year-old daughter, Lydia, died at the scene, while her 5-year-old nieces died at area hospitals. Milberg and her 3-year-old son, Easton, survived.

The driv­er of the truck, Jose Mendoza, 24, of Rockford, Ill., was not in­jured, nor were his two pas­sen­gers.

According to the complaint:

The Pierce County Sheriffs Department responded to a two-vehicle crash at 3:41 p.m. on Hwy. 35 in Oak Grove Township. Milberg was traveling home from the Giggle Factory, an indoor playground in Hudson, Wis., with her two children and two nieces when her 2005 Saturn VUE rotated sideways across the roadway into the northbound lane.

Witnesses told police her vehicle appeared to make a U-turn in front of the truck at around 60 miles per hour, which sent the car careening into the guardrail.

Milberg, who investigators found wasn't wearing a seatbelt, was ejected from the car and thrown 21 feet over the rail and down an embankment. Her daughter, fastened in the front passenger seat, was killed on impact.

Milberg, of Centuria, Wis., was transported to Regions Hospital in critical condition, where she later emerged from a coma. Police found prescription oxycodone in her purse; a blood report later showed that Milberg had therapeutic levels of oxycodone and a sedative known as midazolam in her system at the time of the crash.

Two cellphones were found in the totaled vehicle, but a third was recovered at the scene after snow melted nearly four months later. Records showed that the undamaged iPhone, which belonged to Milberg, had a Facebook chat session in progress from 3:32 p.m. to 3:39 p.m. — just two minutes before the crash.

In a collision analysis and reconstruction report, the Wisconsin State Patrol found driver inattention to be a large contributing factor.

"Driver distraction may explain why Milberg deviated from her southbound lane of travel to the outside shoulder before losing control," according to the report.

The State Patrol also noted that the tires on Milberg's SUV were badly worn and unable to channel moisture that may have been present on the road.