Research and determine the cause of the deaths

Recall that in 2007, 3,600 pets died due to contaminated pet food that came from China.
Research and determine the cause of the deaths.
Identify how the food safety of the pet food was compromised.
Identify how many countries were affected.
Assess what steps countries and companies can take to ensure that this does not recur.
Assess what sanctions should be taken to punish the offending country or company.
Write three pages on how this case highlights the uncertainty and safety concerns that accompany a high volume of free trade for a certain product (in this case, the product is pet food).