Some debris reached an altitude of nearly 3 miles before falling back to earth. Two airplanes circling overhead were blown apart by the heavy shrapnel. A one-ton piece of the ship's propeller shaft landed 2½ miles away. Other pieces sailed 5 miles.The blast flattened 20 waterfront blocks and 12 blocks inland. Flaming debris ignited oil, gas and chemical tanks at the sprawling Monsanto complex and three nearby oil companies.