News like this puts a knot in my stomach. It is even worse trying to mail things across the Canada-US border (I won't elaborate on this, but it is a known problem). I now use a courier (e.g., FEDEX or UPS), fully insured, for any shipment across the border. The sad part is - even with insurance, a loss like this is devastating from a collector's point of view... No amount of money could replace the pride and effort to assemble a registry set collection...
I will keep my eye out at coin shows north of the border.