The woman, who was found naked, shouting and setting fires in the apartment, is expected to be charged in her death, a senior law enforcement official said. She was identified as Dimone Fleming, 22, by the official, who spoke on the condition of anonymity to discuss an ongoing investigation. The boys’ names have not been released. Police were initially called at 7:20 p.m. to the family shelter at Echo Place in the Mount Hope neighborhood in response to a 911 call about an emotionally disturbed person. But they left without finding the children, who were in the bathtub, covered with a sheet or towel, police said. A second call half an hour later about the children brought police back to the scene, where the bodies were discovered. The law enforcement official gave this account: When police first arrived, they were confronted with a chaotic scene, with Ms. Fleming burning items on the stove and items strewn everywhere. The bathroom door was off the tiny kitchen and looked like a closet door. The police may not have tried the door. They were also told by a shelter employee — incorrectly, it turned out — that the boys were with their father somewhere outside the facility. Police left at around 7.50pm after an ambulance took Ms Fleming to St Barnabas Hospital, where she remained on Sunday. Deputy Police Chief Louis De Ceglie said the second 911 call came in around 7:55 p.m.: a report that two babies at the same location were not breathing. Officers returned to the apartment and found the two children with stab wounds, he said. They were taken to Columbia Presbyterian Hospital but died from their injuries, he said. On Saturday night, a family friend, Michelle Rivera, 23, said she came from Queens when she heard what had happened to the children she had “seen growing up.” Describing herself as a “street family,” she said she was close to the children’s father, Columbus Canada. Ms. Rivera was visibly upset as she described the mother’s behavior. “She always had a problem with her significant other,” Ms. Rivera said. He said the mother displayed a short temper around her children, for example getting angry when they cried for a bottle. “He never had patience,” Ms. Rivera said. “Everyone offered their help.” On Sunday, neighbors and loved ones assembled a makeshift memorial of cardboard boxes sheltered from the rain by a board outside the building. Next to a vase of white flowers, notes were written in black marker: “Rest easy baby boys” and “Rest in peace Dashawn + Baby O.” Mr Canada, 31, came to the memorial and stood quietly in the rain, comforted by some other people there. Ms. Fleming has a history with the city’s child welfare agency, the Administration for Children’s Services, but few details were available, the senior law enforcement official said. The agency filed a case shortly after the birth of her eldest son that she was unable to care for him, but it was unclear if she was eventually removed. ACS said it was investigating the case, but declined to offer more information. Someone with the same name and date of birth as Ms. Fleming was arrested on child pornography charges in Pennsylvania in 2018, court records show. The disposition of the case was unclear. In recent years, New York City has annually recorded about a dozen homicides of children under 10 classified as domestic, according to police statistics. Murders of multiple children were rare. But last year, a Queens woman was charged with murdering her infant twins, and in September a mother was charged with drowning her three children in the surf at Coney Island. Charlotte Obiri, 47, a neighbour, said on Saturday she knew Ms Fleming from the neighborhood and often saw her with her children and their father on the street, at the store and in nearby Echo Park. Mrs Obiri was visibly shocked as she described seeing the two boys being shot down. “They took the baby out and worked on it – and then the little boy, they took him out in a garage and he looked lifeless,” she said. “He was naked and looked lifeless. I still see the image in my head.” Mrs Obiri and other neighbors tried to process the chilling scene and the fact that the children’s mother was in custody. “I feel sick,” Ms Obiri said. “I puked”. Liset Cruz and Kimiko de Freytas-Tamura contributed to the report. Susan C. Beachy contributed research.