A deadly earthquake struck the city of Kathmandu, Nepal on Saturday and leveled whole sections of the city. More than 4,000 people are reported dead, and up to eight million have been affected. Aftershocks have subsided, but life is anything but normal. Rescue crews are working to rescue people buried or stranded in the destruction. Food, water and medicine are a great concern.

There's been a swift global response to the crisis. China, Germany and the US have all donated money and aid, along with many other countries. But money and aid are not guarantors of success. 

"It's called a 'disaster' for a reason. It's never going to look that pretty in the first couple days," Juliette Kayyem said Tuesday. Kayyem is a former Homeland Security administrator with experience in triage following natural disasters.

"I had to deal with this with [the 2010] Haiti [earthquake], with some of the challenges of the deployment" of services, Kayyem said. "I was coordinating on the receiving end — the adoption and then the movement of Haitians over here if they were really sick or couldn't be helped."

Kayyem laid out the brutal calculus required to save the greatest number of survivors.

"To the extent that we're worried about the American hikers or the orphans — you have to be cold and calculating, but just get that out of your head. What is most important now is logistics, and the movement of water, and military assets, to save as many lives as possible."

Kayyem said the recovery process will be messy. "You have no infrastructure. That's just the nature of it."

Traditional evacuation methods are out in the steep Himalayas, too.

"Large helicopters cannot land in Nepal. They cannot land in Nepal, which means you cannot grab 50 people and get them out of there. You're doing ten people at a time, and that requires more time, it's more dangerous. And so, all these countries are trying to help, but there's only so much help you can give."

>>Juliette Kayyem is a weekly Open Mic guest on BPR. Kayyem hosts the Security Mom podcast.