NOVA Season 9 Episode 14 The Hunt for the Legion Killer

In NOVA season 9 episode 14, titled "The Hunt for the Legion Killer," viewers are taken on an investigative journey to uncover the source of a deadly illness that had spread throughout an American Legion convention in Philadelphia in 1976. As many as 221 attendees became sick, and 34 died as a result of the mysterious ailment, which was later identified as a strain of pneumonia.

The show begins with archival footage and interviews with survivors of the outbreak, who describe their experiences of falling ill and being hospitalized. Next, NOVA delves into the scientific process of identifying and tracking down bacteria, which requires teams of researchers to analyze samples from the environment, human tissues, and other sources.

Members of the Centers for Disease Control and Prevention (CDC) and other experts are interviewed about their involvement in the investigation, discussing the challenges of tracing the path of an elusive microbe. Meanwhile, viewers witness contemporary experiments that recreate some of the conditions that may have allowed the bacteria to thrive, such as the use of air conditioning and water systems that were contaminated.

One of the key discoveries made in The Hunt for the Legion Killer is the identification of a previously unknown type of bacteria, which was eventually named Legionella pneumophila. NOVA shows how these particular microbes had likely been thriving in the water tanks of the convention center's air conditioning system, which circulated droplets of bacteria-laden mist throughout the crowded and poorly ventilated venue.

As the scientists work to piece together the clues and track down the source of the illness, viewers are given a firsthand look at the process of scientific investigation and the intricate, multi-disciplinary work that goes into discovering new pathogens. Along the way, there are moments of tension and drama as scientists race against the clock to prevent further infections and work to develop treatments and preventative measures.

Ultimately, The Hunt for the Legion Killer provides a fascinating look at the intersection of public health, scientific research, and crisis management. By shedding light on the meticulous process of identifying a deadly pathogen and tracing its origins, NOVA highlights the crucial importance of working together to prevent and contain outbreaks of infectious disease.