Willie Garson, who played art expert, later crime scene cleaner Gerard Hirsch, on the H50 reboot, has passed away. He was only 57.

According to IMDb, he appeared in 9 episodes, but I only found references to 5 of these in my reviews:

His character -- which turned into a "beloved cast member" -- was extremely annoying, constantly slobbering over Kono, played by Grace Park. When Kono disappeared from the show because of sex trafficking issues on the mainland (and Grace Park's departure, rumored to be over pay equity), Hirsch got hot pants for Tani instead!