Prayers and remembrances were held this week for Kayla Mueller, the 26-year-old American who was confirmed dead after being held by ISIS militants for a year-and-a-half. The White House confirmed the news of her death, but it was unclear how or when she died. Mueller was a Christian aid worker who went to Syria in 2013 because she felt called to work with the refugees there. Her family members and friends said she leaned on her Christian faith. In 2014, while in captivity, Mueller sent a letter to her family. She said, “The thought of your pain is the source of my own, simultaneously the hope of reunion is the source of my strength. Please be patient, give your pain to God.” President Obama said he was heartbroken over Mueller’s death. He also defended the U.S. government’s efforts to rescue her and other Americans who have been abducted by ISIS.