On the treacherous Khumbu Icefall, enormous crevasses can open and close without warning -- triggering avalanches. None more deadly than the avalanche two years ago that killed 16 and injured dozens.
Mountaineer Garrett Madison and his team are back on Everest for the first time since that terrible day, but the memory still lingers.
"We heard on the radio that had happened and we couldn't communicate with some of our climbers, then we knew we had lost some teammates."
Among the missing was one of Madison's most trusted Sherpas, the Nepalese locals who know the mountain best. Madison and his team kept searching until they found his body.
The number of climbers this year is down by 40 percent, but Madison is glad to be back in business. And this year, he's chosen a different route to the summit. It's longer, but safer.
"I would say we're a little more cognizant of the hazards in the Khumbu Icefall, and we avoid the icefall on the west shoulder which collapsed in 2014," Madison explained.
"Now the route goes more to the center or the right side, to avoid that hanging ice."
Madison's Sherpas are now equipped with radio beacons and are receiving higher pay, part of the new reforms for local guides since the avalanche.
"We're looking forward to having a great expedition and getting everyone up safely and back with all their fingers and toes."