Kayla Mueller: Obama confirms IS hostage's death
American aid worker Kayla Mueller - who was being held by Islamic State - has died, President Barack Obama has confirmed.
Ms Mueller's family said they were "heartbroken" at the news, and released a copy of a letter she had written in captivity.
Confirmation of Mueller's death comes days after Islamic State claimed the 26-year-old had died in a Jordanian air strike.
