First thoughts on the Chalk Mallard accident is that those PT6 turboprops wouldn't take kindly to the maritime operating environment. Think sulfidation of turbine blades. You wouldn't need a large drink of water down an intake, just the relentless attack of salt to eventually weaken a blade or its fir-tree root. It's like rust.
I'll mount a photo of a sulfidated blade if I can find one. The only protection is to run a rinse-rack using very clean water. P-3 Orions and S-3 Vikings do that all the time at NAS rinse-racks (aka birdbaths). If a PT6 high-revving turbine wheel let go, or even just spat a blade and achieved a nasty imbalance, it could probably take the whole wing with it. That scenario accords with what's been reported thus far (smoky engine + explosion + wing separation).
Sulfidation, if not addressed continually, can create real havoc with a turbine engine, particularly if it's got a reverse pitch capability to help induce and ingest the salty marine air.
AFAIK all the Allison explosions were similar sudden events.... and wholly uncontained. The last one on my last squadron was anyway.