At least a few thousands to a lakh of different species of fish weighing 30 tonnes to 40 tonnes got chocked to death in the Rampally Lake in Medchal district on Sunday, in what is said to be first incident of the kind here. As soon as the reports came in, District Collector M.V. Reddy deputed senior officials including the Tahsildar, to the lake in Keesara mandal and set in motion an investigation. There were different versions about what could have happened, ranging from pollution of the water caused by drainage flowing into the lake to the heat. District Fisheries Officer E. Balaiah said that the intense heatwave and the effect on the water by way of reduced oxygen content in the water could have led to the fish dying. He said water samples had been collected and sent to the laboratory for an investigation. Vice-President of the local Fishermen Cooperative Society E. Anjaiah said that he strongly felt that pollution could be the cause. Mr. Anjaiah wanted officials to look into the matter and take steps to ensure that such a situation did not recur. He also sought financial assistance from the Government for the loss to fishermen. While pollution could not be the sole reason, locals said it was a fact that several small and medium industrial units in the surrounding areas of Kushaiguda, Kamala Nagar, Chandrapalli and Nagaram discharged their effluents including drainage into the Rampally lake.