For 10 stomach-churning minutes on the YouTube video, bus monitor Karen Klein tries her best to ignore the stream of profanity, insults and threats directed at her by seventh-graders on the last day of school.
They call the upstate New York woman a "troll," an "elephant" and a "f---ing fatass" with "ugly-ass ears." They poke and prod her, and at one point a boy says, "If I stabbed you in the stomach, my knife would go through you like butter."
When Klein, 68, tells them, "Unless you don't have something nice to say, don't say anything at all," a boy responds, "Why don't you shut the f--- up?"
Throughout it all, her tormenters laugh at their own cruelty, egging each other on. Finally, when Klein breaks down, the kids goad her about the tears running down her face. "I'm crying," she says. One boy replies, "Yeah, you're probably missing your box of Twinkies."
A student captured the incident Monday on his cellphone video and posted it to first to Facebook and then to YouTube. The reaction has been outrage at the students, the launching of a police investigation — and a worldwide avalanche of donations for Klein.
The international crowd-funding site Indiegogo.com set out to raise money to send the grandmother of eight on vacation. By Thursday, more than $378,000 had been pledged.
"I've got these nice letters, emails, Facebook messages," Klein said on NBC's Today show. "It's like, wow, there's a whole world out there that I didn't know. It's really awesome."
Klein said it took "a lot of willpower" not to respond to Monday's jeers from at least four seventh-grade boys riding the bus operated by the Greece Central School District, in suburban Rochester. "I was trying to just ignore them, hoping they would go away and it doesn't work," she said. "Trust me, they didn't go away."
Klein, who worked as a Greece bus driver for 20 years and as a bus monitor for the past three, learned of the video through Facebook. She didn't see it until she was summoned to the bus garage.
"It was like 'wow,' " she said. "I can't believe it happened. … It was just plain mean."
The Indiegogo site was set up by Max Sidorov, a 25-year-old Toronto nutritionist. "I saw the video and really felt for Karen," he said. "I have some experience with bullying from when I was young and what they were doing to her was just heartbreaking.''
The outpouring of support has far exceeded Sidorov's expectations. "I thought it would get a few thousand dollars, maybe,'' he said. "But maybe she could retire on this."
Klein described her tormenters as "regular, normal kids" and said that "one on one, they're okay. Just don't get a bunch of them together. That's when the trouble starts."
Names of the boys involved have been posted on the Internet.
The father of one of them told ABC News that his "heart broke" when he saw the clip, but added, "My family's received death threats. He's a 13-year-old kid. It was a stupid mistake and he's paying for it, but I just think it's a little out of control."
Greece School District superintendent Deborah Hoeft said the boys will face "strong disciplinary action" when they return to school in the fall.
Klein says she didn't want the students to face police charges but would like to see them "grounded all summer, or maybe all year."
And she would love an apology.
Information from the Democrat and Chronicle (Rochester), Salon.com, Associated Press and WPTV.com was used in this report.