State Police are investigating the death of a woman along Interstate 95 north of Lincoln late Thursday afternoon as an apparent suicide.

Police say 26-year-old Heidi McGovern of Lee stepped in front of a tanker truck, holding her two-year-old son, Enoch. McGovern was killed instantly and her son was thrown from her arms, away from the truck, and landed in the passing lane of the highway.

The crash happened around 4:30 p.m. in Township 2 - Range 8, which is about four miles north of the Lincoln exit.

McGovern had left suicide notes behind at her home, according to Maine Department of Public Safety spokesman Stephen McCausland.

The toddler remains hospitalized at Eastern Maine Medical Center in Bangor with serious injuries. The woman's husband remains at the hospital with his son. McGovern was also the mother of an infant, who was elsewhere at the time of the incident, McCausland said.

The tanker truck is owned by Irving Oil and was driven by 59-year-old Kenneth Gray of Bucksport.