Very hard day today

Today, I went down to my daughters, basically as a peacemaker. My stbx son-in-law, his dad and brother were there, helping him get his stuff as he moved out, officially today.
My son-in-law loaded what he could today and as he came and kissed his kids before he left, tore me apart inside.  It was like 1972 all over again for me.  When my wife and I separated, my kids were 8, 6, and 4. His are 14. 12 and 8.  I felt the sorriest for my 14 year old grand-daughter.  She understands what is happening but, he is moving behind his dad's house. where he and my daughter started their marriage and home 16 years ago.  He is living with his parents, till he gets him a mobile home moved in and set up where they used to live and where his oldest daughter took her first steps.  This is only about 6 miles from where my daughter will be living so, they will see their dad when he is home, off the railroad.
His dad came and shook my hand and thanked me for coming down and keeping the peace.  He is a Deacon in his church.  I told him between he and I, we would see that our grandkids were taken care of and have what they need.
I will not soon get over this.