A fatal outbreak of Legionnaires Disease will be the topic of a special coroner's hearing this week.

Wanaka coroner Trevor Savage will be in Christchurch to consider the fatal cases which occurred in August 2005. Three people died in the outbreak and more than a dozen were infected. A number of cooling towers were checked at the time and infected water was found at the Christchurch School of Medicine and at fertiliser manufacturer Ravensdown.

The inquest will delve into the possible causes and sources of the outbreak.

Legionnaires is a type of pneumonia caused by Legionella, a bacterium found primarily in warm water environments such as air conditioning systems.