WALTON, Ky. (FOX 56/AP) — The Boone County Sheriff’s Department confirmed four individuals were stabbed around 9 p.m. Sunday.

According to the sheriff’s statement, deputies responded to an apartment in Walton involving two adults and two children with multiple stab wounds. The woman, Monique S. Pena, 31, and children, 12-year-old Nikki Romero Pena and 3-year-old Katie Farrell-Pena, were pronounced dead at the scene, the statement said.

The man, Matthew Farrell, 36, was taken to a hospital with serious injuries.

Farrell suffered stab wounds to his torso, neck, and upper body and has been discharged from the hospital, authorities said on Monday. He is cooperating with the investigation

The stabbing was isolated to the residence, and deputies said they do not believe any outside suspects were involved.

The investigation is ongoing.

The Associated Press contributed to this report.