Authorities have revealed that Kristopher Karolkiewicz, who was found dead along with his wife and six children in a burning house in Michigan, is the suspect in the murder-suicide case. The 47-year-old allegedly murdered his wife, Mandy Karolkiewicz, 39, and their six children, before starting the fire in numerous places throughout the house. He died by suicide.Who was Kristopher Karolkiewicz? All on Michigan man who killed wife, 6 kids and himself (@mandykarolk/TikTok)The children have not been named. Authorities said there were four boys aged 15, 12, 11 and 5 and two girls, both 11, per Fox News Digital. Two of the children were adopted.Also Read | Who were Mandy and Kris Karolkiewicz? Michigan couple ID'd after being found dead with their 6 kids inside burning home"The cause and origin of the residential fire remains under investigation by Michigan State Police arson investigators. However, preliminary indications are that the fire was intentionally set in numerous places throughout the interior of the residence. The family pets also perished due to the fire/smoke," the sheriff's office said in a press release.Who was Kristopher Karolkiewicz?Ottawa County investigators said that Kristopher, who worked for the American Heart Association, left his job in the weeks before their murders, Local 4 reported. He worked there from September 2023 until earlier this month, when his “employment ended” in July 2026, the organization reportedly said in a statement.According to the organization, Kristopher served as national vice president of sales and marketing, supporting the division responsible for CPR and first aid training and products. He worked remotely from his home, and did not work in the American Heart Association’s local Michigan offices or with its local Michigan operations.“As an organization with professional staff who are dedicated to helping others, we are devastated by the news out of Grand Haven, and our thoughts are with the loved ones of those who lost their lives in this tragedy,” the statement said.Also Read | Michigan family deaths motive: Chilling details revealed after 8 found dead in burning home; sister speaks outThe family was found dead inside their Grand Haven Township home on Friday, their relatives said. The house was engulfed in flames.Authorities are now investigating the deaths as a potential murder-suicide, the Independent reported. Some of the family members had gunshot wounds, Ottawa County Sheriff’s Captain Jake Sparks said. Authorities put out the flame and then found the family.“We don’t have a cause of death at this point. We’re looking into that,” Sparks said, per People. “We believe everybody that was involved in the situation is in the residence … It’s a complicated scene, a complex scene.”He added that the fire was “suspicious,” adding that police are investigating whether it was “intentionally set.”