Authorities in California have arrested two women who ran a children’s daycare out of a home after two toddlers drowned in a pool there recently. Nina Fathizadeh, 41, and Shahin Gheblehshenas, 64, face counts of felony child endangerment resulting in death as well as criminal negligence, said news releases from police and prosecutors. The arrests come after three people in New York City were charged in connection with the death of a toddler who was poisoned by fentanyl inside a daycare center in the Bronx in September. Three other children survived exposure to the potent opioid at the daycare in the New York City case. That daycare was also run out of a residence, bringing scrutiny to that style of operation. An estimated 12 million children are in some type of daycare in the US. Fathizadeh and Ghebleshenas ran Happy Happy Daycare in San Jose prior to their arrests. On 2 October, Happy Happy called emergency responders for help after three babies fell into a pool at the home. All three babies were brought to a hospital in critical condition, and two one-year-old boys died there, San Jose police have said. Meanwhile, a two-year-old boy received treatment for injuries that were not considered life-threatening. Investigators have since said that there were four children in Happy Happy’s care at the time of the drownings, and a fifth was about to be dropped off. One person was in charge of watching the children after a colleague called in sick and Ghebleshenas had reported to another daycare. According to prosecutors, Fathizadeh was preparing breakfast, had left one of the children in a crib and allowed the three others to go into a backyard play area without supervision and out of her line of sight. That playground stood next to a pool that was closed off by a 5ft tall fence, but Ghebleshenas’s husband had propped the barrier’s gate open to water plants and had failed to close it again, officials said. Fathizadeh noticed one of the children floating in the pool when she went to check on the babies after about five minutes, investigators said. She was performing CPR on that child when her brother grasped the situation and spotted the two other children also floating unconscious in the pool. The brother of Fathizadeh reportedly removed both of the other children from the pool, dialed 911 and attempted CPR. The local district attorney, Jeff Rosen, said all members of the public – including Happy Happy’s operators – had “a responsibility to watch over little children in your care like a hawk”, as NBCBayArea.com reported. “Now it is our responsibility to make sure that these defendants are held accountable for this avoidable and heartbreaking tragedy,” Rosen said. Citing Rosen’s office, the San Francisco Chronicle reported that Fathizadeh and Ghebleshenas could each receive up to 16 years in prison if they are convicted as accused.