Read more on this story from CNN affiliate WDRB.
(CNN) -- An Indiana woman shot her three children and set the family's house on fire before turning the gun on herself, police said.
The bodies of the four were discovered Friday, when police in Austin, Indiana, responded to the home to conduct a welfare check.
"Upon arriving, the officer had to make a forced entry into the residence," Indiana State Police said Monday in a statement. "Once in the residence, he saw parts of the home had suffered recent fire damage and also located four deceased persons in the home."
The state police assisted with the investigation, which preliminarily concluded that 30-year-old Amanda Bennett shot the children -- 14-year-old Jasmine Abbott, 9-year-old Katelynn Bennett and 4-year-old Ryan Bennett -- before starting the fire and shooting herself.
"While the investigation remains open until autopsy reports are finalized, indications are this case is a tragic case of murder/suicide that claimed three innocent lives along with the suspect of the murders, Amanda Bennett," the police statement said.
All four apparently died from gunshot wounds to the head. Amanda Bennett and Katelynn Bennett also suffered smoke inhalation, police said.
The family's dog was also shot, but survived and was being treated at a veterinary clinic, authorities said.
Jasmine, the teenager, had made references to marital problems between her parents and a possible divorce, friend Karen Barrett told CNN affiliate WDRB.
Indiana State Police spokesman Sgt. Jerry Goodin told CNN that authorities examined online content as part of their investigation, including a posting purportedly from Amanda Bennett that blamed her husband, according to WDRB, saying, "You got what you wanted, no wife and no kids."
However, the reasons for the shootings remain unclear, Goodin said.
"The only person that knows the motive is Amanda," he said.
Austin is about 35 miles north of Louisville, Kentucky.
CNN's Ashley Hayes contributed to this report.