The most detailed account yet of the Sandy Hook slaughter

The most detailed account yet of the Sandy Hook massacre has been written by Edmund Mahony and Dave Altimari of the Hartford Courant.
It is a well-written, compelling narrative. 
As businessinsider.com reported, "The details are beyond horrific. The only positive note is that decisions by two teachers, Kaitlin Roig and Victoria Soto, may have saved the lives of nearly 20 children.
Soto was shot and killed in the massacre. Roig survived."

You can read Business Insider's summary here.