I think it was called "A Mother's Thoughts." It was a rather dreadful poem written from the viewpoint of a mom a few weeks after armageddon, reminiscing about her child that didn't survive. In one part, the rebellious kid says, "I can take care of myself in snow, sleet or rain. Besides, if I die, I'll feel no pain." And at the end, the mom says, "You know, son, it's funny, no matter how hard I try- as far as feeling pain, neither do I."
My dad used it in one of his public talks, so bits of it are burned indelibly in my memory, but I'd love to get my hands on the whole thing. I asked him recently for a copy, but he said he'd 'misplaced it.' :P