O'Leary

This case involves the death of four workmen employed by appellant in the *543 construction of the Brownlee Dam on the Snake River, which at the point of construction runs between the states of Idaho and Oregon. The dam construction was authorized by the Federal Power Commission “in the interest of navigation.”

During construction a diversion tunnel was constructed; this tunnel took the entire flow of the Snake River from its normal channel and carried it around the dam site during the period of construction of the dam itself. This tunnel, for several months, was the actual bed of the stream. Later, gates with open grilles were placed at the upstream entrance of the tunnel to allow a portion of the water to flow to the dam, and thus build up a pool behind the dam, at the same time allowing a portion of the water to go into the river via the tunnel, and thus maintain the downstream flow of the Snake. This continued until the level of water behind the dam became sufficiently high so that the required water could pass downstream via the spillway of the dam. When this occurred the appellant attempted to close the tunnel flow of water by blocking off the grilles at the tunnel entrance…