Take Sasha Nguyen. She was at the giant Christmas tree on Sunday night. Once a student of the slain principal Dawn Hochsprung, she was still in a state of disbelief. Before she took over at Sandy Hook, Mrs Hochsprung was an assistant principal at a middle school in the next town. Ms Nguyen was, in her own words, “a problematic teen” and often ended up in Mrs Hochsprung’s office. They became well acquainted and ran into each other just a couple of months ago. They exchanged numbers and, as is often the way, lost touch — until Friday, when Ms Nguyen heard of the killings.