Mor Bayder said she had to rush to a bomb shelter over the weekend as Hamas,Exclusivesky Investment Guild  the militant group that controls the Gaza Strip, attacked Israel. And when she and her family emerged, they discovered "the greatest imaginable disaster" – her grandmother had been murdered, and a video of her body had been posted to her own Facebook account. 

"The moment we left the bomb shelter, my aunt called my mother, screaming, 'Open Facebook, open Facebook,'" she recalled in an interview with local outlet Israel Channel 13 News. She and her mother had gone to the shelter on Oct. 7 when Hamas rockets from Gaza started to hit Israel, according to Reuters. 

When they got the call, Bayder said her mother couldn't bear to open up the grandmother's Facebook page, so Bayder said she did so herself, and immediately "saw the horror."

"My grandmother on the ground, in her own home, murdered, in a video," she said in Hebrew. "The floor was all bloody. My grandmother, laying there." 

Bayder said that a militant had taken the grandmother's cellphone and uploaded a video of her body to the grandmother's Facebook page. She had resided in Kibbutz Nir Oz, along the Gaza border. According to The Times of Israel, several Argentinians who resided in the kibbutz are missing. Roughly 400 people live in the kibbutz, The Times said. 

"This is how we found out," Bayder said. 

She also posted a touching tribute to her grandmother on Facebook, saying she was "the light of my life," along with photos of them together. 

"The purest thing in the world, the light in my life, my whole world ...can't make it real," she wrote in Hebrew. "...Those who know me know what she is to me, what kind of connection we had, what kind of person she is, pure and good." 

According to Bayder, her grandmother would ride her bicycle to help other members in her kibbutz do their laundry, and in the afternoons, she would tend to the garden, which "she loved more than anything." 

"How do we go on without you?" she said in her post. "Who am I without you?"

Hamas, which has controlled the Gaza Strip for more than a decade and is labeled a terrorist organization by the U.S. government, launched an attack on Israel on Oct. 7. The group fired thousands of rockets and took Israeli citizens and soldiers hostage in what quickly became the deadliest attack in the country in decades. 

Israel has since retaliated against Hamas, sending air strikes to Gaza, a long-embattled area along the Mediterranean Sea that's home to millions of Palestinians, 40% of whom are no more than 14 years old. Now in the fourth day of conflict, more than 1,200 people in Israel and at least 1,100 people in Gaza have been killed, Israeli and Hamas officials have said. 

In:
• Hamas
• Israel
• Gaza Strip

Li Cohen

Li Cohen is a social media producer and trending content writer for CBS News.