A woman struggling with mental illness and her disabled son were found dead in a Bronx house of horrors Friday, with her 4-year-old daughter apparently trapped alone inside with the bug-covered corpses for days, subsisting on chocolate, according to authorities and relatives.

Lisa Cotton, 38, and her 8-year-old son, Nazir Millien, were declared dead at the tragic scene.

The woman’s 4-year-old daughter, Promise,  was found covered in chocolate on her mom’s bed by an older sibling who came to check on the doomed family.

Neither body had signs of trauma.

Cotton, who had asthma, may have died of cardiac arrest, authorities told her dad, Hubert Cotton, while Nazir, who was born prematurely and had a feeding tube, might have tragically starved.

Promise was brought to a local hospital in stable condition, the family and cops said.

It’s unclear when the mom and her son died or how long the girl had been alone inside — but neighbors had been complaining of a foul odor that smelled like “death” for weeks.

Cops conducted a welfare check on the family Tuesday at the East 231st Street apartment in the Wakefield section after receiving an anonymous 911 call. 

No one answered the door of the second-floor unit.  Neighbors told the officers they hadn’t  seen Cotton or her kids in two weeks, sources said.

But responding officers did not hear any noise or notice any odor, and had no reason to break down the door, police sources said.

“They said they’d be back in a few days,” a neighbor said of the cops. “One of the social workers said she was trying to get a court order to have the door broken in.”

The shocking discover was finally made Friday night after a concerned Hubert, 71, got a call from his daughter’s    landlord asking if she’d moved out.

“I had been trying to call her for days and she never answered . . . I figured she didn’t answer me because she didn’t want me to talk to me,” Hubert told The Post Saturday.

He sent Cotton’s oldest daughter to the  apartment to check on them.

“When she came in, [Nazir] was slumped over,” still in his chair, he said.

The young woman then looked for Cotton, and instead found Promise “feeding herself with chocolate” on her mother’s bed, he said.

“She picked her up and ran out and called the police,” the weeping father said.

According to a transcript of the young woman’s Friday night 911 call, the young woman had seen “bugs crawling on” Nazir’s body.

Nazir was “so small. I held him in my palm. Like a bird, like a young bird,” the devastated grandfather recalled.

He is now caring for Promise in his Bronx home.

The traumatized girl was curled up in a chair in her grandfather’s home Saturday, silently watching cartoons when The Post visited.

“She hasn’t said anything. She’s a baby. She looks at me sometimes, you know? Like she knows something,” Hubert said of the child. “We don’t know anything, we’re trying to find out.”

Hubert,  who is originally from St. Kitts, said his daughter struggled with what may have been bipolar disorder.

He now wonders  how he’ll lay her and his grandson to rest.

“I’m sorry. . . . Two of them,” he said through tears. “How am I going to get the money? To bury both of them?”

The horrific deaths “feel fake,” said Lisa Cotton’s brother, Raheem Smith.

“I don’t understand what happened,” he said.

Neighbors were also left with questions.

“The landlord hadn’t done wellness checks, people had called, neighbors called,” said Eric Perez, who lives upstairs from Lisa Cotton. “It just smells like rat infested . . .  the exterminator said the same thing — the smell is similar to rats and even death.”

The mother had an Administration for Children’s Services case pending against her, police sources said.

She was arrested in June 2021 on child abandonment charges after she was caught acting erratically, swinging her then infant daughter around in a stroller and lighting a wig on fire in front of a commercial strip on White Plains Road, the sources said.

When cops arrived, they found her walking away from the child. The case was later sealed, authorities said.

The mom had “episodes,” claimed another neighbor who declined to give her name.

“One time she threw paint out the window and she has been talking about the devil,” the neighbor said, adding, “About a year ago, she was out here talking about the devil. . . . I didn’t know what was going on.”

The mom appeared to be suicidal, said another resident who claimed the mom had gone to the building’s rooftop a couple of years ago with her son with apparently deadly intent.

“She wanted to commit suicide with the boy,” the neighbor, who gave her name as Sharlene, said.

Another time, the mom proclaimed, “I am going to kill everybody on the block,” Sharlene, a home health aide, recalled.

“It hurts because it’s somebody who you know, somebody who you see, somebody who you were close to, and now it’s gonna be when you come outside, you see no one there and that’s gonna hurt,” she said. “I hope the little girl is going to be okay.”

An ACS spokesperson said the situation is now under investigation.

ACS should have done more for the kids, said another resident who gave his name as Mark.

“We called police and they took her away,” he said of the roof incident. “In a sense I blame ACS. They should have done more from the first.”

“Why leave the kids with her?” he added. “When they came to check on her, they shouldn’t have left. They should have been forceful.”