As if the Jordanian pilot being set to flames in a cage wasn’t enough, U.S aid worker Kayla Mueller has been confirmed dead.

Mueller was the last U.S citizen to be held hostage by Islamic State (IS) militants in Syria. She is said to have been heading back to Turkey when she was ambushed on August 4 of last year.

There had been many attempts to rescue her by U.S officials and her family but they were unfortunately unsuccessful, and this week IS sent proof of her death.

This time, the proof of a hostage being dead was handled differently than before. Instead of IS sending a worldwide video out of a murder, IS claims they are not responsible for the death of Mueller. They said she died in a Jordanian air strike, but the Pentagon believes there is no doubt IS killed her, according to BBC News.

All fingers seem to be pointing at IS yet again, especially after Jordan admitted that Mueller had not been killed in the air strikes following the Jordanian Pilots death.

Although it is not completely certain how Mueller died, it is still a heartbreaking situation for another family of an IS hostage.

Mueller’s death leaves many with questions as to what exactly led to this tragedy and who is responsible for it. Regardless of who is to blame it is still a heartbreaking situation for yet another family of an IS hostage.