This fatality occurred to a patient undergoing chemotherapy treatment in a private hospital in Brisbane.
Looks like they think the transmission occurred through a warm water system, and most likely during a shower where the patient could have breathed in the contaminated water droplets.
Trying to drag some stuff out of my memory (so I haven;t referenced this), usually less than 5% of an exposed population even develop symptoms, and then it usually is more harsh on at risk (e.g. Reduced immune system). It's also a bacteria that is present
in most cooling tower systems apparently, it's just usually at very low levels and so considered safe.