How does the safety record of the twin piston Diamond DA-42 compare to the single piston DA-40? Its fairly well known that the Diamond DA-40 has one of the smallest fatality rates of any GA plane. The Diamond DA-42 is a twin engine aircraft with a very similar design to the DA-40. 

Now, it has been shown that, in general, twin aircraft are not that much safer than single because the added complexity of operation removes the added safety from engine failure. However, the DA-42 is much easier to fly with FADEC control of the engines and a lot of automation. 

Is the DA-42 safer than the DA-40?
So it appears that Diamond answered this question for me. 

See this page:
http://www.diamondaircraft.com/about-diamond/safety-features/



From this chart, it would appear that the DA42 has a slightly higher accident rate, and of those accidents, even more are fatal (which makes sense due to the higher speeds). Still loads safer that the SR22 though, and I'd personally prefer the 42 over water as well.