ISIS Hostage Kayla Mueller Confirmed Dead It's still unclear how she died By Kate Seamons, Newser Staff Posted Feb 10, 2015 9:17 AM CST 58 comments Comments In this May 30, 2013, photo, Kayla Mueller is shown. (AP Photo/The Daily Courier, Jo. L. Keener) (Newser) – "We are heartbroken to share that we've received confirmation that Kayla Jean Mueller has lost her life." That from the parents of the 26-year-old American, who was being held by ISIS in Syria. ISIS on Friday claimed Mueller was killed during airstrikes carried out by Jordan, when the building in Raqqa she was being held in collapsed. ABC News reports by way of a White House National Security Council rep that the family "received a private message from Kayla's captors containing additional information" over the weekend, and that information was authenticated by US intelligence. CBS News specifies that the message was an email that contained an image of the body; it didn't make clear the cause of death, only that it happened "recently." There is no word yet from US officials on how she died, reports the Washington Post. Mueller had been kidnapped while leaving a hospital in Aleppo in August 2013; her parents describe her as a "devoted humanitarian." President Obama released a statement that reads in part, "On behalf of the American people, Michelle and I convey our deepest condolences to Kayla's family—her parents, Marsha and Carl, and her brother Eric and his family—and all of those who loved Kayla dearly. At this time of unimaginable suffering, the country shares in their grief." Mueller becomes the fourth American ISIS hostage to die; she was the only known US hostage remaining in ISIS' hands.