Seems like Caravans are having trouble again in Hawaii... A number of dead stick landings and a ditching occurred the last few years. Here's the most resent...

http://www.staradvertiser.com/news/breaking/20150423_Mokulele_airlines_flight_forced_to_make_emergency_landing.html?id=301060191

I seriously doubt that the Caravans are having trouble.......those PT-6 engines are about as reliable an engine as there is. But they do need fuel, and preferably u contaminated fuel.

First thing I'd do is look at the fuel source.

MTV

The infamous Molokai ditching...

My good buddy (I bought his AZTEC), ditched off Kalaupapa because the compressor exploded. It was running some funky STC that extended TBO. (1) lady died in the water, one guy swam to shore (crazy, but remarkable), and rest were airlifted to Kaunakakai. Very sad.

I just had lunch with Clyde (pilot) last month and he said he smashed into the panel (or something) and got a pretty good size bump on his head. Now flying for Aloha Air Cargo, he does not fly singles anymore.

I've got around 2400 hours flying Caravans for a fedex feeder, and a lot more than that running around behind PT6's and was around when Fedex had a rash of engine failures. With no information, I'd suspect CT wheel corrosion at the base of the compressor blades. If they develop that, the blades can't flex, and will set up a harmonic and come apart. Several of our Hawaii airplanes had that, as well as many of our CONUS birds.