Cadillac Repair: cadillac seville sls 2000, cadillac seville sls, cadillac seville

Question
i have been diagnosed with  a cracked block.  the car is not subject to extreme temperatures, has not been wrecked and all scheduled maintenance has been performed.  family car original owners, 77,000 miles.  
is there a history of defects in this model? what would cause the crack? and what should the repair cost be?

Answer
It is RARE that a block is cracked unless the anti-freeze was not sufficient to keep the engine coolant from freezing. I would definately get a second opinion just to make sure that it IS the block that is cracked or it may be probable that one of the head gaskets is leaking and only requires replacement of the head gaskets.