Police in Placentia, California, suspect a father killed his two daughters and then himself in a murder-suicide on Wednesday.

Around 12:30 a.m., authorities found the body of the father on the sidewalk outside of the home, NBC Los Angeles reported. The bodies of the girls, who were believed to be about 9 years old, were discovered indoors.

Sgt. Bryce Angel recalled the gruesome scene during a conversation with reporters. “It’s horrific. It’s not something that anyone would want to see. To see the tragic death of two young children, in one word it’s horrific,” he said.

Fox Los Angeles reported that first responders attempted to save the children, who may have been twins, upon their arrival, but the two were eventually pronounced dead at the scene. The unnamed victims suffered several stab wounds while the father appeared to have self-inflicted stab wounds.

Investigators believe the man killed his children and then fled outdoors to take his own life.

The mother of the two children and a female, who was related to the father, were in the home when the incident occurred. Authorities suspect the women may have been sleeping during the murders and were unable to stop the man once they were awake.

Angel told ABC 7 that crisis counselors have been made available to help the relatives of the victims cope with the incident. 

“It is extremely tragic for the family. It’s just one of those things that we hate to see happen. We’re trying to get to the bottom of this, why it happened,” he said.