A Toronto man's online fundraising campaign for a 68-year-old upstate New York grandmother is nearing $450,000, after a video showing the woman being bullied to tears by children on a school bus went viral.

The victim of the deluge of taunts, insults, slurs and threats of violence was Karen Klein, a school bus monitor in the Rochester, N.Y., suburb of Greece.

Her tormentors were a group of four 13-year-old boys.

In a profanity-laced exchange, the 10-minute YouTube video posted this week showed the students calling Klein "fat," "ugly" and a "troll," and jabbing her with their fingers as she wept, apparently trying her best to ignore the comments. The children continued to abuse her verbally after she removed her sunglasses to show she had been crying.

Bus monitor Karen Klein, 68, was abused by a group of students in an incidents that was captured in a 10-minute video that has been posted on YouTube. Bus monitor Karen Klein, 68, was abused by a group of students in an incidents that was captured in a 10-minute video that has been posted on YouTube. (YouTube)

One student taunted: "You don't have a family because they all killed themselves because they don't want to be near you."

Klein's oldest son killed himself 10 years ago.

Klein told CBC's Mark Kelley Thursday night on Connect that she decided not to press charges against the children "because these kids — they're kids."

"I'd hate to see it go in their file or whatever. They're only 13 years old," Klein said. "Middle-school children are a different breed of children."

Hugs from strangers

While Klein said she was surprised to learn a video of the incident had been posted to YouTube, she was even more taken aback by the flood of support she received from strangers who viewed the clip.

The video has been viewed more than 1.8 million times within just two days.

"I can't believe the people and how nice they've been. I mean strange people stop by and they give me a hug," Klein said Thursday.

Backlash against Toronto fundraiser

The online fundraising campaign was spearheaded by Max Sidorov, of Toronto, who saw the bullying video and set a goal to raise $5,000 to send Klein on vacation.

Another Indiegogo.com campaign, "Love for Max Sidorov too," was later set up by a secondary fundraiser to express gratitude to Sidorov for his original effort, accumulating roughly $2,000. Sidorov received backlash for seemingly profiting from the viral buzz himself. He had earlier linked his Indiegogo page to the Klein effort and also pointed viewers toward a book he wrote and was selling on Amazon.com.

The Indiegogo page for Sidorov has since been removed.

Among those affected by the footage was Torontonian Max Sidorov, who created a page through the online fundraising service Indiegogo.com for Klein.

Sidorov, who told CBC News he was a victim of bullying as a young immigrant from Ukraine, noted that Klein only earns $15,506 a year. He had set a goal to raise $5,000 for her to take a much-needed holiday.

"Lets give her something she will never forget, a vacation of a lifetime!" Sidorov wrote on the page.

But the fundraising drive soon wildly surpassed expectations. As of 8:30 p.m. ET Thursday, more than $375,000 had been pledged to go toward Klein.

Hopes for retirement

In her first conversation with Sidorov since the money was raised, Klein said on Connect with Mark Kelley that she was overwhelmed by supportive emails, Facebook messages and flowers.

"It certainly has been an experience. One I'll never forget," she said.

Klein said she hasn't yet decided where she might go on vacation.

Earlier in the day, Sidorov told CBC Radio's Carol Off on As it Happens that he hoped the money would give Klein the freedom to stop working and take it easy.

"I think she's going to retire with this money, and I hope she does. It's enough money to send her on a very much earned retirement," he said.

As for Klein's tormentors, she said the father of one offered her a sincere apology and added that a written apology from his son would be forthcoming. She has also requested a written apology from another of the youths.

Death threats for boys

Meanwhile, a deluge of people have demanded harsh punishment for the boys featured in the video.

John Auberger, supervisor for the Town of Greece, said in a press conference the suburb was likewise shocked by the hurtful nature of the taunts.

"We, too, are outraged by the behaviour of this group of students and want to emphasize that the actions of a few do not reflect our community as a whole," he said.

The boys remain under police protection.

"They've received death threats," Greece police Capt. Steve Chatterton said Thursday. "Their families have been threatened. We have custody of one of their cellphones, and he had over 1,000 missed calls and 1,000 text messages threatening him. And he's 13 years old. That must stop."

Police said it's not clear if they committed a crime under NY State law. Klein said she simply hopes the kids learn a lesson and act respectfully.

With files from The Associated Press