https://www.cbsnews.com/boston/news/conan-obriens-parents-thomas-ruth-died-obituary-boston/

Dr. Thomas O'Brien died Monday at age 95, and his wife Ruth Reardon O'Brien died at 92 years old on Thursday, according to their obituaries.

So sad for Conan and his siblings. But passing away in their 90's they had good long lives. They got to see Conan hosting tv programs.