May 2018 marks 20 years since the multiple fatality fire in HMAS Westralia during a training exercise off the coast of Western Australia. It should serve as a reminder of the dangers inherent in military service including training exercises. For those of us in the health professions the fire in HMAS Westralia should also lead us to reflect on the long-term mental health impacts for those involved in such incidents. The fire in HMAS Westralia resulted in the immediate deaths of four of our personnel and the management of a further four personnel treated for injuries – with both immediate and long-lasting impact on the injured and their family and friends. However, it also resulted in significant and long-lasting mental health problems for other personnel involved. A review of about half of the personnel from HMAs Westralia who were still in the Navy 6 years after the fire suggested that nearly one in five reported significant symptoms of post-traumatic stress disorder (PTSD). This review was prompted by the death, by apparent suicide, of a survivor of the fire who was medically discharged from the Navy, primarily due to PTSD resulting from the fire. This study only looked at those still in the Navy after 6 years – with speculation that this figure may be conservative, as the sample may have overly represented those who were still well enough to remain in the Navy, and not included those who may have been most affected and who had to leave the service in the years following the fire. There were also at least seven publicly reported legal cases by personnel claiming significant mental health problems arising from their involvement, from the 94 survivors. The fire in HMAS Westralia came at a time when PTSD was known and understood in the Royal Australian Navy (RAN), a structured response was provided, and a mental health screening program was in place. Reflecting on the fire in Westralia should remind us of the need to be vigilant for the potential long-term mental health care needs of people involved in trauma in the military.