Code Black, about County Hospital in Los Angeles and the emergency doctors who work there, is a portrait of the space where more people have died and been saved than anywhere else in the United States.

Guest blogger Heather McIntosh of Documentary Site looks at the 'stubbornly observational' body of work of documentary director Frederick Wiseman (High School, Titicut Follies, La Danse - Le Ballet de l'Op´ra de Paris).