News of a Nanny killing two children and then trying to kill herself has caused public outrage, and many just want to know why.

The nanny, identified as Yoselyn Ortega, alledgedly murdered two young kids she babysitted with a kitchen knife and then tried to kill herself Thursday inside a posh upper West Side apartment, according to the New York Daily News.

The children's mother, Marina Krim, walked into her W. 75th St. apartment about 5:25 p.m. and found a horror scene: her 6-year-old daughter Lucia and 2-year-old son Leo lying motionless in a blood-soaked bathtub, each with multiple stab wounds.

On the bathroom floor laid Ortega, critically injured, and the kitchen knife she used to carry about the deranged attack, police said.

Neighbors could hear piercing shrieks echoing outside the eight-story building known as La Rochelle.

"I could hear really loud, hysterical screaming - world-class screaming," said an elderly neighbor, who lives down the hall from the Krim family on the second floor, according to NYDN. "I didn't want to go out of my apartment."

Neighbor Sandy Marcus said the mother "looked beyond frantic."

One bystander said of Krim: "She was mumbling words, incoherent," said Stephanie Herman, 58. "I can't imagine experiencing something like this.

"This is a very family-oriented area. You see moms and their strollers a lot. Many people hire nannies here. This is everyone's worst nightmare."

Daily News reported that the children's father, Kevin Krim, CNBC's general manager of digital content, was on a plane from California when the kids were found. He returned home Thursday night.

"It's awful. It makes me sick to my stomach," said Jill Pace, 27, who lives in the area. "I can't even look at the building. You have to wonder what goes through someone's mind to do such a horrible thing."

New York Daily News called the crime "barbaric." The public feels the same way about the tragedy (comments from New York Daily News and Daily Mail articles).

One commenter said, "Oh my God. You don't know who to trust anymore. I am so deeply sorry for the pain this mother and father must be going through. I pray for them." Another said, "My heartfelt condolences to this family today and always. I know how devastating it is to lose a child but to lose two and in this way is just unfathomable. Prayers for all involved, Christine in Florida." One more said, "Just.Plain.Awful. its more than dusty in this room. I can't even begin to imagine this families pain. I wish I could reach out and hug them and that it would help."

Some had doubts about what actually occurred.

One commenter said, "Do they know for sure she committed the crime? Is it possible someone else in the building did it?" Another said, "Something doesn't sound right about this, and I mean aside from the death of the children. No, what I mean is that on another site (dailymail), after the Nanny had killed the two children, she then slit her own throat in an attempted suicide. However, to actually slit a persons own throat is actually quite difficult and from the above article, it appeared that the Nanny was happy person. Now, anything can make a person snap, but I have a feeling that there's a large chunk of what actually took place missing from the events described."

Some tried to guess why the nanny would do such a thing: "I literally want to cry. The nanny was probably jealous of the family's lives and wanted to ruin their perfect family she was so jealous of. She should have been able to kill herself but didnt..people who really want to commit suciced get the job done."

Another said, "It's either two things. She was having a thing with the husband and it went wrong. The other she was into Brujeria!"

Other commenters were adamant about what Ortega's punishment should be if she indeed was the one to do something heinous like this.

One commenter said, "My heart is broken for that family. I'm at a loss for words. I feel horrible for the little 3 year old who is going to ask where her big sister and little brother are. I hope the nanny lives and while in prison gets what she deserves." Another said, "Put her in a cell, give her a knife and see if she can get it right this time." One more said, "Glad the nanny was arrested. Now what. I hope. PRISON WILL BE HER. LIFE HOME can we deported her back to homeland?"

The media is still trying to figure out why anyone would do this to two innocent children with a loving family like the Krims.