Very sad. I can't imagine the horror of losing my children, and my heart goes out to the family.
Hopefully, this tragedy will spur folks to wear life jackets, take safety precautions such as proper attire, and prevent future such occurrences. “the father and two siblings did not resurface" implies a lack of life jackets, which other articles seem to corroborate. No one intends to capsize but maybe now more people will plan for a capsize. It's not just life jackets, either. In such weather, and with such cold water, hypothermia can set in very quickly. It's why you often see kayakers on the Sound wearing dry suits--they don't plan on going swimming, and kayaks are quite stable, but they've planned for the possibility of ending up in the water.