Gord, I think Maleri is saying that the Panda
diesel itself is frozen, not the starter, and the teeth on the flywheel star
gear are chewed off.
If I'm right on that interpretation, Maleri, the first task is to find why the
engine froze and free it. Since it happened suddenly and I'm guessing that that genset has
oil pressure and
water temperature warnings or even shut-downs, something like ingesting
water into a cylinder sounds more likely. So, release the belts and put a breaker bar socket wrench on the forward crankshaft nut. If you cannot turn the
engine over, then pull the injectors and see if you've got water in a cylinder, and try again with turning it over.
If this is the cause, the likely culprit is the vent on the
exhaust loop clogging and allowing water to be sucked in as the engine cools.
There are other causes, but by now you would have learned enough to either tackle the job yourself or brief your
mechanic.
In any case, the flywheel will have to come off (big job, but not technically challenging) and either the entire flywheel replaced or the star
gear replaced, depending on whether it's one piece or two.