The Islamic State is claiming one of its hostages, a 26-year-old American female aid worker, is dead, according to the Site Intelligence Group, a website that monitors extremists The terrorist group claimed she died when a Jordanian aircraft struck the building in which she was located in Raqqa, Syria. Jordanian fighter jets bombed Islamic State sites on Thursday, after the militants burned to death a captured Jordanian pilot. The State Department told Sky News earlier this week it was working "very hard" to free the aid worker.