I’ve just read some very thorough and well thought out advice to help out family friends of the bereaved. One of the worst things that happens is when people don’t know what to say, so they don’t say anything. It’s equally uncomfortable for us, but we would rather talk about our children instead of pretending like they never existed. Please, please read and take the advice to heart the next time that you encounter someone that has lost a child.
http://www.griefgratitude.com/2014/10/what-to-say-and-not-to-say-to-bereaved.html