A botched murder-suicide left a 46-year-old woman dead and a teenager wounded when a violent domestic dispute exploded inside a Long Island home last week, police said.

Marcos Leal, 57, fatally stabbed estranged wife Adriana Barbosa, 46, and attacked a teen who also was in the couple’s Farmingville home before turning the knife on himself and trying to commit suicide Thursday night, police said. Leal survived, cops said.

Long Island man Marcos Leal allegedly killed his wife Adriana Barbosa and attempted to kill himself at their home in Farmingville last week. Adriana Paulino Barbosa / Facebook

A teenager who is related to the couple was also injured in the botched murder-suicide. Dennis A. Clark for NY Post

The horror unfolded just after 8:15 p.m. at the home on Granny Road when a 911 caller alerted police to a domestic incident seeming to spiral out of control at the home.

Suffolk County police officers raced to the residence and were met with a gruesome scene, finding Barbosa and Leal both with stab wounds along with the teen relative who had also been injured during the attack, according to authorities.

“Very, very, very, shocked. I never have problems with him, very nice people,” stunned neighbor Benvinda Viera told the local ABC affiliate of the accused violent hubby.

Barbosa was rushed to Stony Brook University Hospital, but doctors were unable to save her and she was pronounced dead shortly after arriving.

“Those who met you know that your qualities were countless, and that you deserved the best this world had to offer,” a shattered friend of Barbosa’s wrote on Facebook.

“I am deeply disturbed and outraged by such brutality coming from those who should protect you.

“My only peace of mind in the midst of all this is knowing that you are finally at peace, and no one else can make you sad or hurt,” the pal said.

The teenager wounded at the home was transported to the hospital and treated for non-life-threatening injuries, police said.

The child is related to the couple, according to police, but they didn’t specify how.

Barbosa was pronounced dead after being rushed to Stony Brook University Hospital. Adriana Paulino Barbosa / Facebook

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Leal, who authorities say attempted to take his own life after killing Barbosa, was taken to the same hospital with serious injuries but ultimately survived.

He is now charged with murder, criminal contempt and endangering the welfare of a child.

It is not yet clear what caused the deadly confrontation between Leal and Barbosa. Adriana Paulino Barbosa / Facebook

Investigators have not yet released details on what sparked the deadly confrontation or the circumstances surrounding the criminal contempt charge, but said the investigation remains ongoing.

Leal, who is currently recovering in the hospital, is expected to be arraigned at a later date.

“Oh, my goodness — blue and red lights, cherries and berries we call them, about a dozen to two dozen cars swooping in here at mega speed,” neighbor Dr. Richard Dark told ABC of the law-enforcement response to the crime scene.

“Three ambulances,” Dark said. “One left early. Probably didn’t need it. One left quietly, unfortunately.”