It's always hard to think of something to say when someone passes away. You can say that you are sorry for their loss and offer your assistance if they need anything. After losing someone, it's always nice to hear good stories about their loved ones and the memories that other people have. Also, the pain for them will last beyond the funeral. Call them in a week or two and see how they're doing,
. take them out for lunch, or just listen in case they need to talk.