Authorities said Wednesday a 27-year-old woman strangled her children, then hanged herself in their Lake in the Hills home.
At 2:55 p.m. Tuesday, Lake in the Hills police responded to a medical check call for an unresponsive subject at a home on Daybreak Drive, police spokeswoman Amanda Schmitt said.
Huntley firefighters, who were first on the scene, found Carla M. Lopez-Mejia, her son, Ezequiel Garcia, 11, and her daughter, Ariana Garcia, 8, dead, Schmitt said.
It's unclear who made the 911 call, which came from outside the home. Police don't know where the father of the children was at the time, Schmitt said.
"We have been in contact with immediate family," she said.
"Preliminary scene findings suggest that this is a murder-suicide confined to these decedents and this location and that there is no threat to public safety," according to a news release from the McHenry County coroner's office.
Autopsy results Wednesday determined that Lopez-Mejia was hanged and her children died of strangulation, McHenry County Coroner Anne K. Majewski said later Wednesday. Majewski said the official causes of death won't be made until the investigation is complete.
Lake in the Hills police said the children were found on the second floor and Lopez-Mejia on the first. They said they could not give out any further information while the investigation continued.
Neighbor Jennifer Goodrich said her youngest daughter played with Ezequiel and Ariana.
"The little girl and my daughter were similar in age," she said. "I didn't know the mom real well other than just 'hi.' We talked occasionally and went back and forth about the kids."
The conversations never got too personal, Goodrich said. Goodrich said she saw the family out the other day cleaning up after their dog. Ariana came over to play with her daughter.
She saw Lopez-Mejia on Monday sitting in the backyard while the dog was out.
"It's hard to wrap your head around," she said. "I don't know what was going on in her life and what caused her to do that. I feel bad for the kids. And I'm sad for her that she felt that was the best option. I don't know what happened."
Lopez-Mejia previously was a student at McHenry County College, spokeswoman Christina Haggerty said. She was last registered in 2015 and has not attended classes at the school during the past year.
Ezequiel was a sixth-grader at Marlowe Middle School, and Ariana was a third-grader at Martin Elementary School, both in Lake in the Hills.
"We offer our condolences to all who were connected to this family and to the entire school community," Huntley Community School District 158 Superintendent John Burkey wrote in a statement posted on the district's website. "This terrible tragedy has affected all of us in the Huntley 158 family, and the grief that accompanies news such as this will take time to process as students, staff, and the community all attempt to come to terms with it. The district has brought together counseling and bereavement support services resources from all of our schools to be available for students and staff."
The students' classmates at both schools have been informed of the facts known so far, officials said.
"Students have been encouraged to come to any staff member to express their feelings and ask questions," Burkey wrote. "Students will respond to this tragedy in different ways, and it is important for both schools and families to support them. Any reaction is normal in the grieving process and can range from withdrawal to crying to anger. It's important for us as adults to listen carefully to our children and help them through their reactions and feelings regarding this tragedy."
Anyone seeking counseling help can call the McHenry County crisis hotline at (800) 892-8900.
• Daily Herald staff writers Lauren Rohr, Charles Keeshan and Chacour Koop contributed to this report.