China-Nepal border mudslide fully unpacked: What exactly happened

At 10:52 a.m. Beijing time on August 26, a glacier collapsed high in the Himalayas. Six to seven minutes later, the ice-rock avalanche it unleashed flattened Gyirong Port in China's Xizang Autonomous Region — then kept going, surging downstream into Nepal.

Since then, Chinese rescuers have pushed in by land, air and water to reach the port through a canyon where the road was gone, the river was blocked, and the risk wasn't over.

But some questions didn't end with the flood. What exactly happened on the China–Nepal border? Was it just a mudslide? Why was there no warning? Why did it hit Gyirong Port the hardest? And why has the rescue proven so difficult? To answer them, we trace the disaster from the glacier to the gorge. Watch the full breakdown.