On August 20, 1944, American engineers detonated two mines filled with six thousand pounds of explosives under Japanese positions on Songshan (Pine Mountain). The Japanese 113th Regiment, 56th Division, had thoroughly fortified the mountain, from which it could rain down artillery on the Burma Road. The Chinese 8th Army had been fighting to take it since the end of June, but the Japanese offered stiff resistance. Finally, with most of the Japanese trapped near the summit, American engineers suggested mining underneath. The explosion at 0905 hours on the twentieth buried alive at least forty-two Japanese soldiers and allowed the Chinese to resume their advance, though the battle continued until September 7.