The Red Cross Blood Bank was seen in the Season Nine episode, "The Death of Eric Cartman".
Background[]
While at Doctor Lindsay's home looking for answers as to why Butters could see Cartman's "ghost", the TV mysteriously turned on behind them. The channel was showing several escaped convicts holding Red Cross Blood Bank employees hostage. The building was surrounded by police and a news crew was reporting on the dangerous situation. Cartman, thinking he needed to perform a good deed for his spirit to go to Heaven, decided to help the hostages at the Red Cross. Thinking he was invisible, Cartman walked through the police line into the building and began acting like a ghost; throwing books and papers making spooky noises. This significantly confused the convicts, which made it easy for the hostages to escape to safety.