Well here is the positive part. No water in the oil
What gets me is the freeze plug right below it should have blown out not the cast iron block ugh!!
Ayuh,... Maybe because it's a Core plug, from the sand casting used to create the part...
They only work as freeze protection when it freezes, 'n thaws...
If it freezes solid 1st shot they usually don't...
Clean it up, 'n epoxy over, then go Boatin'...