According to the Imdb:

The cast of "Barney Miller" stepped out of character on a retrospective episode that aired in May of 1979 to offer a tribute to Jack, who had died a few months earlier (of cancer of the esophagus) during the show's fifth season. The episode recalled some of his best moments on the show.

In the late 40s he first met "Barney Miller" creator Danny Arnold while sharing the nightclub stages in the mid-West early in their show business careers.

Was interned in a camp for Japanese-Americans in Utah during WWII.

His last words to Hal Linden as he was being wheeled into the operating room before his death were "It must have been the coffee". This was a reference to the running gag of his character Nick Yemana from Barney Miller having the reputation for making horrible coffee.

He was one funny man. I recall watching the news and they announced he died. I was so shocked. I watched the retrospective, it was very touching, sad and funny. How honored he would've been. BTW, I had back surgery several years ago and the anesthesiologist happened to resemble broadway actor Joel Grey. When I told him this he laughed and told me he was Jack Soo's anesthesiologist many, many years before and that Jack was coming out from the anesthesia, Jack looked at him and was somewhat coherent and told him, "Hey Joel, what are you doing here?" I was laughing so hard. The anesthesiologist was telling me other stories abt Jack and they were all funny. He said Jack was one of the nicest people he had ever met.

I also enjoyed Jack Soo in Flower Drum Song (now available on DVD). He got to dance and sing in that film. He passed on about 8 months before I was born but I totally love his work on Barney Miller. Yemana was one of my favorites, and I'm happy that the cast and crew put together a retrospective in his honor. BTW, thank you for sharing the touching story, Irene!!

Jack Soo was one of my favorite actors -- he could do more with just one line than anyone else -- thanx for the information and the stories -- much appreciated.

Jack Soo was truly one of a kind...and is still missed!