The pilot reported that the aircraft was departing empty from the Snake Creek Fish Farm after delivering a load of freight. The main fuel tanks were 3/4 full and the auxiliary tanks were full. After the aircraft speed had passed Vmca and the aircraft was becoming airborne, the right engine failed. The pilot closed the throttles, selected the right propeller to feather, landed the aircraft and commenced braking. He assessed that insufficient runway remained for a successful stop so he initiated a ground loop to the left. Just before the aircraft stopped, the nose leg struck a mound of earth that had been hidden in the grass. This caused the nose gear leg to collapse and both propellers were damaged. No reason for the engine failure could be established. The grass on the airstrip was long. This may have resulted in lower acceleration performance than the pilot had anticipated.