I am going to attend the funeral of a coworker, and wonder what should I say to the family of the deceased? I've never met the family before. Do I introduce myself and explain that I worked with "John"? How much detail do I go into? I worked with John on only one project, and have since moved into another department. We were never social friends, only work acquaintances. Should I even attend?
Attending a funeral is a personal decision and entirely up to you. If you decide to attend, then keep your statements to the family brief. You don't need to go into details about your work relationship. Simply shake their hand, and say something such as, "I'm 'Charlie.' I worked with John. He will be missed. I'm sorry."
The family will appreciate that you took the time to attend the funeral.