Q. My colleague’s 19-year-old brother died in a freak biking accident. I attended the funeral and sent a condolence note, but worry about what to say and do when the bereaved comes back to work next week. What is your advice? You’re not alone in your concerns. “Coworkers and managers don’t know what to do with someone who has had a significant loss,” says Rachel Blythe Kodanaz, who coaches the be…