“Thermal runaway” of Lithium batteries

A German actress is happy that she is still alive because the Lithium battery of her smartphone started burning on the couch in the morning and the whole apartment burned out. This is the original German article.
http://www.vip.de/cms/wegen-smartphone-ex-soap-star-tanja-wenzel-bei-wohnungsbrand-verletzt-2607658.html

This problem is related to Lithium batteries in general and can happen in any smartphone, laptop, etc.
A German documentary shows the “thermal runaway” effect of Lithium cells.