These still waters in a lagoon in Western Mexico have turned lethal. The lagoon has become a graveyard for hundreds of thousands of fish. Dead fish are being removed by the barrel-full. Local fisherman say the problem is pollution at the bottom of the lagoon. They are seeking answers. Local authorities say its just nature taking its course. But state investigators are blaming "poor management". Attention has now turned to the wastewater treatment plants that operates nearby.