Oh, I'm so very sorry.
What a difficult thing to have happen, and not once, but twice. The poor children, too. I know that you all loved him, and there'll never be another quite like him.
My children are grown, but they still talk about their favorite rooster, who we lost prematurely, from over 15 years ago. In fact, it's the main reason I'm getting a rooster in my chick order next month. My son wanted one like our Pablo so badly, that I agreed to it, even though my hens have been content without a rooster.
We learn so much from them, and while their lives, even the longest of them, are comparatively short, they make a huge impact on us. Your Sigmund was a rooster who made a huge impact on all of you, I can tell, and when the children have grown, and they still talk about Sigmund fondly, and your grandchildren know about him, your heart will be warmed by it. Honest. (((Hug!)))