This Is Us writer Jas Waters has died at the age of 39 of unknown causes.Waters’ death was announced via the This Is Us writers’ Twitter account on Wednesday (10 June) night, with their statement reading: “The entire #ThisIsUs family was devastated to learn of Jas Waters passing.“In our time together, Jas left her mark on us and ALL over the show. She was a brilliant storyteller and a force of nature.