In your initial post, answer the following questions:

How might the relationship between Mr. and Mrs. M. be affected by this situation?
Should the parents tell their surviving child that he had a twin brother? Why or why not?
If you said yes, at what age would it be appropriate to do this? 
What roles might the grandparents play in this situation? 
What conflicts might result?
What services might be required? 
Do you think this experience would bring the parents closer together or drive them apart? Support your answer.
Do you anticipate the parents would consider having another child?  Why or why not?