(CNN) — The family of Kayla Mueller, an American woman held captive by the Islamist terror group ISIS, said Tuesday it has received confirmation that she is dead.
“We are heartbroken to share that we’ve received confirmation that Kayla Jean Mueller, has lost her life,” a statement from the family reads.
On Friday, ISIS claimed that Mueller had been killed in a building that was hit during a Jordanian airstrike on Raqqa, the militants’ de facto capital in Syria. At the time, ISIS offered no proof to back up its claim, other than an image of a building in rubble.
Mueller fell into the hands of hostage-takers in August 2013 in Aleppo, Syria, her family said, after leaving a Doctors Without Borders hospital.
Her family said it heard nothing until nearly a year later, when ISIS contacted them with proof that she was alive. The militants eventually said they would kill her if the family didn’t pay nearly $7 million by August 13, 2014, according to a source close to the family. What happened after that deadline is unclear.
Mueller, 26, made it her life’s work to help others. After graduating from Northern Arizona University in 2009, she worked with humanitarian groups in northern India, Israel and Palestinian territories, a family spokeswoman said. In Israel, she volunteered at the African Refugee Development Center.
Mueller went back to Arizona in 2011, volunteered in a women’s shelter and worked at an HIV/AIDS clinic, helping to facilitate events and providing local coordination for World AIDS Day, the family spokeswoman said.
After working for a year as an au pair in France, she traveled to the Turkish/Syrian border to work with the Danish Refugee Council and the humanitarian organization Support to Life, which assisted families who had been forced to flee their homes due to the civil war in Syria, the spokeswoman said.
In a YouTube video produced in October 2011, before the rise of ISIS, Mueller said she supported a sit-in that protested the Syrian regime.
“I am in solidarity with the Syrian people,” she said. “I reject the brutality and killing that the Syrian authorities are committing against the Syrian people.”