Gabriel Greenbaum and his classmates at Rambam Mesivta High School in Lawrence, New York raised $2.4 million for the victims and families of the Jerusalem terror attack that killed five people and left 9 others injured.

The campaign spearheaded by Greenbaum and his compatriots, via a series of crowd-funding websites was so successful that Greenbaum will be creating a new campaign for Druze police office Zidan Saif who was fatally wounded in the same attack.

Both campaigns are ongoing.

Greenbaum told reporters that the amount of money raised “ kept going up and up, I was just in shock. We had, like, an impact.”

The day that the attack occurred, administrators of the high school called an assembly and explained what had happened to the students. Following the assembly, Greenbaum’s 10th-grade class held a brainstorming session as to how they could respond to the attack, and what they could do in the face of terror. They quickly arrived at the idea of a crowd-funding website.

“I told the kids, ‘You’ve got to do something, you can’t just sit,’” said Rabbi Aryeh Young, a teacher at the Long Island school. “And they all immediately gravitated toward the idea.”

The students set up a website through the crowd-funding service CrowdRise. “By 6 o’clock that afternoon it was viral,” said Young. “We raised $18,000 by the end of the first day. By the end of the second day it was $24,000, and it kept ticking up.”

Young heard about a similar endeavor which was started by the President of a New Jersey brokerage firm by the name of Ira Zlotowitz. Young reached out and offered Zlotowitz to work together.

“I’d never spoken to him in my life, he’d never heard of our school before,” said Young. “There was zero connection. I googled his name, I found his cellphone number on the Internet, and I cold called him at 9 o’clock at night,” Young said.

The next morning at 5:45 a.m Zlotowitz drove all the way to Long Island to speak to the school following prayers.

“I saw him walking in and I realized the magnitude of what’s happening, how many lives we can touch,” Greenbaum said. “He walked in, he spoke for two minutes to the entire school, and I think he inspired a lot of people.”

Young said that Zlotowitz told the students that they were his heroes. Zlotowitz combined a website he started with the effort spearheaded by Greenbaum to launch www.theharnoffund.com.

“People say to me, ‘It’s amazing you jumped in to do what you did,’” said Zlotowitz. “And I turn around and find out there was one kid in 10th grade, and he was the first one.”

“He started Tuesday morning, the other site started on Wednesday, the next week they merged together and really started rolling,” Zlotowitz said.

The Orthodox Union organization got involved and began emailing people all over the world, and the donations came pouring in. Contributions came from places as far-flung as Moscow, Alaska and Australia.

The attack took place on November 18. Less than two weeks later, the goal of $1.16 million was achieved and was matched by an anonymous donor who contributed via alternative channels.

“I didn’t think kids our age could raise that much money by starting a website,” said Josh Dublin, a 10th-grader at Rambam Mesivta.

Greenbaum said, “We can’t bring their fathers back,” but this endeavor certainly helped.

According to a report in the Jerusalem Post Rabbi Avi Berman, the director general of the Orthodox Union in Israel, said the funds will go a long way to help the families of the victims, some of whom he said “are in a tough time” financially.

Berman, who has has ties to the community said the sum raised through www.theharnoffund.com is the only major financial contribution they have received, although neighbors have pitched in and helped where they can.

In light of the success of the Har Nof campaign, Greenbaum decided to create a parallel effort for the family of Druze policemen Saif.

“After he already got his credit, and everyone said how amazing it is what he put it together, when everything died down, he decided to go help a Druse officer,” Zlotowitz said. “That I think is the true story today.”

Greenbaum’s parents donated the first amount and paid for the domain name www.harnofhero.com. They contributed $180- an amount symbolizing life.

“The goal is to provide the same support for Saif’s family as they have already generated for the families of the Jewish victims,” Zlotowitz said.

“The fact that Saif had no connection to the community and was not even Jewish makes him all the more deserving of their support,” Greenbaum said.

“He was being a hero.”