These bricks weigh about 6 lbs (2.7 kilos). The men carry bricks in a load, well in excess of 50 kilos. That they keep their balance as they bear them along narrow gang-planks from boat to boat and down to the riverbank is one of the many miracles of Bangladesh. There are about 10,000 brick kilns in Bangladesh. The dust and smoke they create is lethal. There is no other natural building material available.