The fire incident in Santa Maria, Brazil, where died 242 people, 123 injuries, repeated aspects already found in similar tragedies in other countries and showed the difficulty of learning with these aspects regard to accident prevention. The disaster occurred when a pyrotechnic component used by a music band emitted heat that reached the polyurethane ceiling, which ignited. This study aimed to analyze systemically the Santa Maria nightclub fire to describe different aspects whose interaction led to the accident. The assembled maps allowed us to conclude that there was an insufficient mechanism of action coordination for accident prevention. It was possible to show that besides the nightclub’s design problems, such as a lack of alternative unobstructed rescue routes, emergency signaling, agility in emergency response, other contributing factors were material weaknesses, lack of training of firefighters and first responders responsible for preventing injuries resulting from the burning of the coating material used for soundproofing the club. Accident analysis based on the AcciMap helped reveal the systemic nature of the complex network of causal factors involved in the fire at the club.