Ontario mother's suicide notes detailed plan to kill her two daughters, ages 4 months and 14 years, police say

Authorities said that suicide notes left by the mother of two children found dead inside the garage of an Ontario home Tuesday have led them to believe that their deaths were an attempted murder-suicide.

“The children were intentionally killed, it appears the mother was responsible for that act," Ontario Police Department Sgt. Bill Russell said during a press conference Wednesday morning.

The bodies of the 47-year-old woman's two daughters, ages 4 months and 14 years old, were discovered inside the garage of a home located in the 500 block of East Tam O'Shanter Street. Investigators said that the 14-year-old had special needs. Their deaths are being investigated as a homicide.

Police said the girls' mother was located unconscious inside the home with injuries and was rushed to the hospital where she is in stable condition. It was unclear if her injuries were self-inflicted, police said.

The father of the two victims called 911 after he discovered their bodies when he arrived home on Tuesday afternoon. He had last seen his daughters when he left for work that morning.

Russell said that there was "strong evidence" that the mother of the children is solely responsible for their deaths.

"Among that evidence is a suicide note left by the mother indicating that she intended to kill the children and to kill herself," Russell said, adding that the mother has struggled with depression.

Police said that two suicide notes were discovered, one inside the home and another in a vehicle. The contents of the notes were not disclosed to the public.

Related: 2 children found dead at home in Ontario; police investigating as homicide

Russell said that there appeared to have been a struggle at the scene and that the girls had "visible injuries," which may have played a factor in their deaths. 

The cause of the death of the young victims remains under investigation, however, the Ontario Fire Department ruled out Carbon monoxide poisoning.

Authorities are waiting for a coroner to provide an official cause of death.

No charges have been filed at this time. Investigators said they have still not had the chance to interview the mother. 

Russell said that the father voluntarily gave them a statement and is cooperating with authorities. He is not believed to have played a role in the girl's deaths.

“The father’s distraught. You figure at this point, he’s lost both his children and his wife is in the hospital,” Russell said. “He’s lost everything at this point.”

The names of those involved have not been released.

The investigation is ongoing.