It was a quiet evening in the working-class West Carson neighborhood — until residents heard the screams.
A woman ran out of a small, white house, a bloody knife in her hand. She screamed at her son-in-law and frantically began dialing her cellphone.
"She killed the babies," she said.
Inside the house in the 1000 block of West 223rd Street, authorities said, the woman had found her 30-year-old daughter, naked and "covered with blood" on a bed next to the neatly arranged bodies of her own three girls. Investigators say that Carol Coronado killed her daughters — identified by relatives as Sophia, 21/2 ; Yazmine, 16 months; and Xenia, 2 months — before stabbing and slicing herself with a kitchen knife.
The girls' father was working on a pickup parked across the street, neighbors said. He screamed when he saw the bloody scene inside his home.
"He kept saying, 'Oh my God, Oh my god,' " neighbor Veronica Ruiz said.
Los Angeles County sheriff's detectives Wednesday were still trying to determine what prompted the slayings the day before. Coronado and her children had never been reported to the Department of Children and Family Services' child abuse hotline, according to sources who have reviewed the case. Sheriff's Lt. Dave Coleman said investigators there were not aware of any previous incidents involving the stay-at-home mother.
Investigators were looking into Coronado's mental health, Coleman said, including whether she might have suffered postpartum depression after the birth of her youngest daughter.
"We still haven't determined a reason," Coleman said. "Obviously, we're going to have to delve into her mental state."
Those who know the family said there was no indication that anything was wrong. Coronado often took the girls on walks up and down the street, a neighbor said. Her Facebook page featured several photos of the girls, including an ultrasound photo.
In a brief interview with The Times, Coronado's father-in-law said she was "trying to go to school and take care of the kids."
"It's real bad," Rudy Coronado, 67, said.
Another relative, John Carrion, said Coronado's husband — who is also named Rudy — was "dazed and confused."
"Right now, he's giving her the benefit of doubt," Carrion said. "He just said he didn't believe he saw Carol — he saw a demon inside her. He said he doesn't blame Carol. He blames the … demon."
Carrion declined to speak further about the children's' mother, saying only that he had never seen her angry.
"I don't know how I feel about the woman right now," he said. "I don't understand what was going on in that woman's head."
Authorities responded to the Coronado home about 5:20 p.m. Tuesday. Neighbors watched as deputies escorted her from the house, handcuffed and wrapped in a blanket.
"She had a zoned-out look and was just looking down," Ashley Madrid, 27, said. "She had dry blood smeared on her face and legs."
Coronado was taken to a hospital for the self-inflicted wounds, which Coleman said included a puncture wound to her chest. She was listed in stable condition Wednesday, and was expected to be booked on suspicion of murder when she was released.
Detectives removed several knives from the home, Coleman said. There was evidence that the girls had been stabbed, he added, but it was unclear what other injuries they may have sustained. Autopsies were scheduled to be conducted Thursday.
"We still haven't established how they died," Coleman said. "But there were stab wounds."
Coleman said the girls' bodies were carefully lined up across the bed. Coronado, he said, was lying perpendicular to them.
Investigators also planned to examine Coronado's medical history. Coleman said she briefly served in the Army more than a decade ago before she left for medical reasons.
Outside the home, relatives assembled a small memorial of flowers, candles and teddy bears. On Wednesday evening, several dozen people attended a vigil for the slain girls, including their father. Surrounded by relatives and friends, he cried and rubbed the photos of his three daughters.
Amid prayers and chants, the younger Rudy Coronado dropped his head to the ground and wept louder. Relatives stroked his back and head.
The girls, Carrion said, were energetic and loved the Disney movie "Frozen." There were plans for a baptism this fall.
"They were the most beautiful babies you had ever seen," he said. "They loved their daddy and he loved them. Pray for my babies, please, pray for my babies. Pray for Rudy. And even pray for that woman."
Times staff writers Nicole Santa Cruz and Garrett Therolf contributed to this report.