An elderly American teacher originally thought to have been captured alive by Hamas in its Oct. 7 attack on Israel was actually killed by the terrorist group that day, her kibbutz said Thursday.

The body of Judith Weinstein, a 70-year-old American-Canadian-Israeli citizen, is still being held in Gaza by Hamas, Kibbutz Nir Oz said in a statement, according to the BBC. It’s unclear how the kibbutz determined details about her death.

Weinstein, who was initially believed to have been the oldest hostage taken by Hamas, “was a poet, entrepreneur, and pursued many initiatives to advance peace in the region,” the kibbutz said, adding that she was a mother of four and grandmother of seven who taught English to children with special needs.

Weinstein’s family also released a statement.

“We are heartbroken by the murder of our mother and grandmother Judy Weinstein Haggai, an American-Israeli-Canadian citizen. Judy was a mother of four, a grandmother of seven, and an active community member of Kibbutz Nir Oz,” the family said, according to The Hill.

The kibbutz confirmed last week that Weinstein’s husband, 73-year-old American-Israeli Gad Haggai, was also among the Oct. 7 fatalities.

President Joe Biden spoke out Thursday in honor of Weinstein’s memory.

“Jill and I are devastated to learn that American Judith Weinstein is also believed to have been killed by Hamas on October 7,” he said in a statement. “This tragic development cuts deep, coming on the heels of last week’s news that Judith’s beloved husband, Gad Haggai, is believed to have been killed by Hamas.”

Biden added that he’s been in touch with the couple’s children.

“They have been living through hell for weeks,” he said. “No family should have to endure such an ordeal. And I reaffirm the pledge we have made to all the families of those still held hostage: we will not stop working to bring them home.”

Kibbutz Nir Oz, which is near Israel’s border with Gaza, was among the hardest hit Israeli communities in the Oct. 7 attack, though exact death and kidnapping totals remain unclear. In total, Hamas has killed more than 1,000 Israelis. Of the 240 hostages it took, around 100 remain in the group’s custody.

Israeli forces, meanwhile, have killed more than 20,000 Palestinians in an aggressive response to the attack funded in part by American tax dollars. Despite U.S. resistance, the United Nations passed a resolution aimed at increasing humanitarian aid for Gaza last week.