It's not clear what might have caused the fault. Olivas told Gizmodo that she'd only been using the official Apple charger with the phone and that she hadn't had any trouble with the device until this week. After the device failed to switch on, she said she took it to an Apple store where employees ran diagnostic tests but found no faults.
"The next morning I was asleep with my phone charging next to my head, my boyfriend grabbed the phone and put it on the dresser," Olivas told Mashable. "He went to the restroom ... and from the corner of his eye he saw my phone steaming and [heard] a squealing noise. By the time he got over to the phone it had already caught fire, he quickly grabbed the phone and threw it in the restroom ... as soon as he threw it in the restroom it blew up and more smoke started coming out of the phone."