HARTLAND, Wis. — Authorities identified the six people who died in an apartment fire in southern Wisconsin as two adults and four children.

All six lived together in one apartment of a four-unit building in Hartland, Wis., police said in a statement. The adults who died were Connor McKisick and Jessica McKisick. The children were identified as a 14-year-old girl, a 12-year-old girl and two 3-year-old boys.

The fire happened in conjunction with a murder-suicide, police confirmed to Spectrum News 1 on Monday.

“Connor McKisick’s gunshot wound appears to be self-inflicted," Hartland Police Chief Torin said. Police said all six victims died of a single gunshot wound.

In a letter to Arrowhead High School parents, Superintendent Laura Myrah identified the 14-year-old as Natalie Kleemeier, who was a freshman at the school. The names of the other children have not been disclosed.

"The entire Arrowhead High School community is deeply saddened by this untimely event," Myrah said in the letter. "Natalie was a student who was friends with and made positive connections with many Arrowhead students and staff members. She was a freshman who was known as a quiet but funny young woman who cared for those around her."

No other suspects are being sought and there is not a danger to the community, according to police. 

Police said they found evidence of a fire accelerant. 

Multiple fire departments and police departments responded and helped evacuate tenants from the building and from apartment balconies, Misko said.

A total of 10 people were displaced by the fire, including two families of four and an adult couple, American Red Cross spokesman Justin Kern said.

Misko said authorities were conducting an “active criminal investigation.” He said Hartland police, the Waukesha County Medical Examiner’s Office and the state fire marshall are all on the case.

Hartland is a village of approximately 9,100 people about 26 miles (42 kilometers) west of Milwaukee.

This story is developing. Check back for updates.