04/05/2016 5:35 PM AEST

After 70 Years Of Searching, Families Of Brothers Separated During The Holocaust Reunite Online

"We cannot believe that we found each other."

For more than 70 years, Abram Belz searched for his younger brother, Chaim. Abram last saw his sibling in 1939, when he helped Chaim escape into the Soviet Union from Poland's Piotrków Trybunalski ghetto.

Abram never saw Chaim again.

Last month, after decades of searching, the brothers’ families reconnected. It was an emotional, bittersweet moment made possible by technology, the help of strangers -- and a stroke of luck. 

Jess Katz, Abram’s granddaughter, explained to ABC News how desperately Abram wanted to find Chaim.

“I don't even know if there are words to describe it, this was all he wanted, he just wanted to know that his brother survived,” Katz said.

Abram wrote countless letters, and even sought the help of Polish and Russian officials and several nonprofits, including the Red Cross. But Chaim couldn't be found.

The brothers were separated soon after the Nazi invasion of Poland. Although Abram had helped Chaim escape, as the eldest son, he felt obliged to stay behind with his parents.

Abram described the next few years during a 1990 testimonial for Steven Spielberg’s USC Shoah Foundation project:

Less than a year after we moved into the ghetto, my grandfather dropped dead in the house. Two weeks later, my 24-year-old sister died of tuberculosis. My uncle who was 26-years-old was shot, his wife and baby were sent to Treblinka where they were gassed to death by the Nazis. The rest of my family was exterminated. My parents were sent to Treblinka and were killed in the gas chambers.

According to The Washington Post, Abram and a cousin were the only two among 60 relatives to survive the concentration camps. 

Abram immigrated to the United States after the war and died in 2011 at the age of 95.

"[Abram] was my hero," Katz, who lives in New Jersey, told ABC News. "He had nightmares every night about the Holocaust, even when he was in his 90s he would have them. But he would still wake up and find a way to be the best grandfather and the best father. He had a lot of struggles and a lot of pain, but he still found some kind of way to live a life full of love and kindness."

Determined to continue Abram’s search for his brother, Katz turned to, a free Jewish heritage website, to find new leads. That search led her to Jewish Facebook groups and Russian forums. 

"I used Google Translate for everything because I don't speak one word of Russian," Katz wrote in a blog post.

Then, one morning last month, she received an unexpected message. 

"I woke up to an email in Hebrew from a woman who told me that she thinks she found my [grand uncle's] son. I was in complete disbelief," Katz said. 

That man was Evgeny Belzhitsky. He was, as Katz soon found out, Chaim's son. 

“We were shaking, we were crying, we couldn’t believe it,” Katz said.

Chaim survived the war and built a life in Sakhalin Island, Russia. Like his brother, he searched for years for his family, to no avail. 

Chaim died in 1970 after battling a brain tumor, never knowing about Abram's survival and life in America. But the brothers' families are now doing their best to make up for lost time.

On April 20, the two families connected via Skype. 

"We sat and told stories, we cried, we shared pictures -- we spoke for four hours and still have so much to cover. We cannot believe that we found each other," Katz wrote in her blog.  

Katz said she hopes her family's story will help other Holocaust survivors find their long-lost loved ones.

"We want to be able to show that there is still hope and online tools that can be utilized to reconnect," Katz wrote on Facebook.