But for those of you who feel they must explain the events to the children in their lives and don't know how, here are a few links that might help.
Here is how some Parisian parents dealt with it (article in English, on mashable.com)
French-speaking parents have the option of downloading for free the special editions produced by the teams behind a series of newspapers aimed at children from the age of 6 onwards (pictured). With clear text and infographics, these give a lot of background information that is key to understanding the events in context. They also provide a lot of testimonials from children themselves about how they felt in the aftermath of the attacks and of the march.
You can find out more about these special editions here (in English). This article also features a handy check-list on "How to talk about it" which I reproduce here: