Learning From Analysis of Rebreather Deaths
The June 2013 issue of Diving and Hyperbaric Medicine contains an excellent article that analyzes the causes of recreational closed-circuit rebreather fatalities. It concludes that while rebreathers have an intrinsically higher risk of mechanical failure as a result of their complexity, this can be offset by good design incorporating redundancy and by carrying adequate alternative gas sources (i.e. 'open-circuit bailout') in the event of a failure. Fatalities may be further reduced by diver training and rebreather designs that minimize the chances of human-machine interface errors.
to read Analysis of Recreational Closed-Circuit Rebreather Deaths 1998-2010 by Andrew W Fock.