Like any mother who suddenly finds herself in a hospital waiting room, Helen Connolly was uneasy.
It was Feb. 28, 2007, and her younger son, Chris, had been taken to the Northwestern Memorial Hospital emergency room — there had been an accident during his Wednesday water polo practice.
Chris, who had turned 15 three days earlier, was a freshman on the St. Ignatius College Prep team, following in the footsteps of his brother, Dennis, nine years his senior. He and Helen were close — he was her later-in-life child, a sweet, still-gawky kid who shared her curiosity and a measure of her intense drive.
She had dealt with the practical details: Her husband, also Dennis, was...