Melamine 'found in milk sold in Chinese shops'

I saw a sad news at Yahoo home pages , it is about melamine. I still don't understand , why it can happened ? The news said that :

Chinese authorities have found melamine in milk sold in stores, state television reported Thursday, widening a scare over contaminated powdered milk in which four people have died.

A nationwide inspection found traces of the industrial chemical in products from three of the country's biggest dairies, CCTV reported, citing the quality control administration.
The inspection was launched after the discovery of melamine, normally used in plastics, in powdered milk.

Miss

Today is Sunday , I just realised that I have been two months stayed at apartment. Yeah..sometimes I miss at my old house but the house is not belongs to me anymore. I felt sad but I do love my new apartment. It is more simple live in here.