The film is primarily the narratives of many first responders, so they play a large roll in the meassage being protrayed. They are seen as heros but also paid the price of their decisions through health issues.
The film is geared towards the general public, all medical terms are explained fairly well. No medical or first response background is necessary, and it is fairly educational for viewers.
The real threats of air quality were covered up due to politics and other reasons, wanting to get america back to work. Instead, the reports were edited and people were sent back into the dirty air to clean up the scene or back to office jobs in the area, with contaminated air surrounding everything. Decontanimation efforts did not start until very late in the process. Bush did not wear a mask and the workers were told they didn't need to, so they didn't. As a result, there were severe health problems afterwards.
The first hand interviews from first responders are compiled in a way that goes through the stories of what heppened, how health information was released and changed. The first repsonder stories are intermixed with testimonies from the EPA workers, showing differences in the science that was found and the press releases disclosing the health concerns. Many tear up upon realizing how their health will hurt their families. The doctors in the area caught onto the trends in poor health and started a monitoring program to make sure everyone got the medical screening and help they needed. The lives of all of the first responders and their families were changed drastically from their public service.