A North Dakota mother sent a chilling warning video to the father of her three children before she stabbed them in a frenzied attack, police say.

Kailey Erhart, 22, allegedly knifed her daughters Morgan, three, and Ava, five months, to death at her Mandan home on Thursday evening, according to an affidavit obtained by KVLY.

She also allegedly knifed her one-year-old son, Colton, but the little boy survived the attack after undergoing extensive surgery. Police say he sustained serious injuries.

Erhart carried out the ‘horrific’ attack after waving a gun at her estranged husband, Cameron, and chasing him and the children’s grandmother out of the house with a knife, the affidavit said.

When police responded at the home, they said they found Erhart covered in blood and holding a kitchen knife to her own throat.

Officers found the three children lying on the floor after following a trail of blood to a nearby bedroom, the filing said. They were unresponsive and had wounds on their necks, per the document.

Before the attack, Erhart texted a video to Cameron warning him to ‘say goodbye to your kids,’ the affidavit said.

The footage allegedly showed her carrying one child with a pistol on her hip.

Erhart was arrested at the scene and faces nine charges, including two counts of murder, one count of attempted murder and multiple counts of aggravated ᴀssault and terrorizing. She has not yet entered a plea.

Kailey Erhart is accused of knifing her three young children in her Mandan, North Dakota home on Thursday in what police have called a ‘horrific’ attack

Her daughters Morgan, three, and Ava, five months, were killed in the attack. Erhart’s one-year-old son survived, but sustained serious injuries

A judge has set Erhart’s cash bond at $3 million, according to Burleigh Morton Detention Center inmate records reviewed by the Daily Mail.

A formal no-contact order has also been put in place, barring the accused killer from contacting the surviving child or family members.

Her preliminary hearing and arraignment have been set for October 6.

Police said that Erhart and Cameron were in the midst of a separation at the time of the ᴅᴇᴀᴅly attack. He allegedly planned to file for divorce.

Erhart had an apparent history of mental illness, with the young mother admitting to having suffered from postpartum depression after Morgan’s birth three years ago.

‘This last month and a half have definitely been some of the hardest times I have been through,’ she wrote in a Facebook post in April 2023, the Daily Mail can reveal.

‘I love Morgan to pieces and I’m so glad she’s here, but my postpartum depression has definitely kicked my ʙuтт at times. Sometimes I feel so alone and stuck like nobody is there for me and I have nobody to talk to and sometimes I wish I would have waited to have Morgan.

‘It’s definitely been a wild ride considering I’ve felt so depressed and I thought Morgan would be better off with me gone, and other times like I don’t know where I’d be without her.’

Erhart, 22, faces nine charges, including two counts of murder, one count of attempted murder and multiple counts of aggravated ᴀssault and terrorizing. She is being held at the Burleigh Morton Detention Center on a $3 million cash bail

Erhart and her husband, Cameron, were in the midst of a separation at the time of the attack

She went on to say that she was ‘one lucky mama to have this little girl with me everyday’ and claimed that ‘adorable’ Morgan has ‘definitely helped me out in more ways then [sic] one.’

Erhart had also been insтιтutionalized over alleged mental health concerns about 12 to 18 months prior to Thursday’s attack, the affidavit said.

She had allegedly threatened to hurt herself and the children but was cleared to be around them after being discharged from the facility.

Erhart told police during questioning that she did not remember what happened during the ᴅᴇᴀᴅly attack last week.

She claimed to have put the children to bed and told officers she believed their throats had been slit before then, the affidavit said.

She did remember holding the knife in her hands when officers arrived at the home, according to the court document.

Mandan Police Chief Jason Ziegler, during a press conference, described the crime scene as ‘one of the most horrific’ that his officers are likely to ever encounter.

‘I want to acknowledge this is an extreme, tragic and heartbreaking incident for the children involved, their families, our community and first responders who arrived on scene,’ he said, KFYR reported. ‘Our thoughts are with everyone that were impacted.’

A GoFundMe campaign has been created to support Cameron and his one-year-old son

Police say Erhart and Cameron got into a physical altercation before her alleged killing spree at their home

Erhart appears in court before Judge Marina Spahr, who set her bail at $3 million. Her preliminary hearing and arraignment have been set for October 6

Police say Erhart and Cameron got into a physical altercation before her alleged killing spree.

She threatened him with the gun she had recently purchased, but he managed to disarm her during the struggle, which saw her bite and scratch him, the report said.

Cameron took the weapon apart and scattered the pieces, police said.

A GoFundMe campaign has been created to support Cameron and Colton during this difficult time.

‘He is a father trying to survive something no parent should ever have to face,’ the fundraiser said.

‘I lost two precious souls in a devastating tragedy after they were murdered by their mother, and the pain is more than I can put into words.

‘Every day, we are carrying unimaginable grief while also trying to stay strong for his surviving child, who is receiving ongoing medical care and facing challenges no child should ever have to endure.’

The fundraiser has already amᴀssed more than $26,000 in donations.