tl;dr, headline is false. Smartphones aren't killing people. Stupid behavior is killing people.

They know better, and they do it anyway.

Smartphones make it easy for everyone to record all of their phone calls, protecting them from phone predators. They provide location capabilities which make it easier for rescuers to find victims of accidents. So on and so forth.

Smartphones are great. Stupid people are going to find ways to kill themselves no matter what tools you place in their hands. It's natural selection.