"We heard a rumble that was the loudest, deepest horrible rumble," Capito told CBS' The Early Show. "Then the earth started shaking so badly that most of us were falling to the ground."
Amazingly, everyone in her group survived the violent quake.
"It was a total miracle," she said.
The Americans were in the middle of a tour sponsored by the World Wildlife Fund when the 7.9-magnitude earthquake rattled China's Sichuan province. The group was trapped for three days in a remote, mountainous area near the .
After the quake struck, the group returned to their hotel from the nature reserve only to find that the building was too unstable to enter.
"We couldn't go in the building. So we had to live in the bus with our bottled water. We had 24 bottles of water for 12 people for three days. And so we had to ration our water," Capito said via telephone.
"The toilet situation was horrendous. That was the worst part. There was about 500 people, refugees coming from all these little villages that could get out. They came into this one area. We had an emergency camp set up," she said.
For three days and three nights Capito and her traveling companions waited for help to arrive.
"We had only rice soup. We were rationed one bowl of rice soup two times a day. There was a small little village store that had some dried raisins, dried plums, that we had to ration each morning."
Finally, on Wednesday, and representatives of the World Wildlife Fund were able to reach their tour group by satellite phone. When the Americans were finally airlifted out by helicopter, what they saw below shocked them.
"I cried all the way. It was absolute destruction the whole way," Capito said. "The whole canyon we flew out of, every hillside had slid down. There was one town that was completely, totally erased. It was at the bottom of the hill where we got off the main highway to go up to the reserve.
"There was no village there at all," she said.
Now relatively safe in the provincial capital of Chengdu, Capito is looking forward to returning home. Though, the reality of her ordeal is just beginning to sink in.
"I feel like I'm actually watching it in a dream," she said. "I don't feel like I'm going through it yet. It hasn't really hit me that it's as bad as it is."
"Until the helicopters got there today, that's when I finally realized this is a serious thing - I'm finally getting out of here. Then all of us just sobbed; we just cried knowing we're going to see our families again. Because during the time, I really thought I was dead. I really thought I was dead on the spot."
Capito knows how lucky she and the other members of her group are lucky to be returning home to their friends and family, but she's still struggling to comprehend the full scale of the earthquake's death toll, which some Chinese officials fear could reach as high as 50,000.
"I'm just so sad for the 15,000 that have lost their lives," she said.