At 12:52, Sept. 5, a 6.8-magnitude earthquake struck Luding County (29°59'N, 102°08'E), Ganzi Prefecture, Sichuan Province. Up to 13:00, Sept. 7, 2/3 of the 72-hour golden rescuing time has gone. Check the video to find out how Sichuan people built the lifeline in the 48 hours.