Obviously, the victim must have been using something that was not genuine Apple equipment (or even made by an authorized third-party.)
Hundreds of millions of people have been using iPhones for about six years, and many of them do idiotic things with them. If an all-Apple system could be lethal, dozens or hundreds of unlucky folks would be dead by now. It's sad that the young lady died, but the blame for her death belong to the maker of the junk charger.
That's not logical. If say 500 million people are using iPhones, and there is a problem that produces a one-in-a-million chance of killing someone, that's 500 dead. We would have heard of that. If a problem produces a one-in-500-million chance of killing someone, then one person dead is exactly what you would have expected.
On the other hand, some statistics from the UK says that there are per year about 13,000 accidents involving electricity, and about 1.2 million involving falls (400,000 on even ground, that is falling over your own feet, lots from stairs, a bit fewer from ladders); couldn't find number of deaths. So there are probably many more people who have died after tripping over an iPhone that for whatever reason was lying on the ground (and many more tripping over Nokia or Samsung phones).