Couple recounts surviving deadly Nepal flood: "I knew I was going to die"

A couple from the San Francisco Bay Area who were on a pilgrimage to Tibet told CBS News on Friday that they thought they were going to die when they saw a mountain of water coming toward them earlier this week.

"I knew I was going to die," Anjana Raja told CBS News. "I knew I was going to die."

The catastrophic flash flooding that struck a mountainous border area of Nepal and Tibet on Wednesday — when a glacier in the Himalayas collapsed and sent torrents of water into the valleys below — has killed nearly 600 people, with an estimated 2,500 more believed to be missing as search and rescue crews frantically scour for survivors.

The U.S. State Department said Friday that about 90 Americans are estimated to be among the missing.

When the avalanche of powerful waters ripped down from the high Himalayas, the melting glacier and debris first hit the Nepali village of Timure, near where Raja and her partner Pattabiraman Venkatesan were with their tour bus.

The couple were making their first pilgrimage to Tibet, an autonomous region of China that shares a border with Nepal. They had driven through Timure, and were in the bus in Nepal's Rasuwa District, near the Nepal-China border, when a tsunami appeared.

"It's like 60, 70 feet, it looked like a tsunami, but dark black," Venkatesan said. "... I could see this monster thing coming down. At that point I didn't know if it was water. I thought it was fire, forest fire, honestly."

Raja said she grabbed Venkatesan by the collar, pulled him and said, "Run," as the two of them jumped off the bus.

As thousands of people ran for their lives, cellphone videos showed some getting swallowed into the churn, while others were able to climb to safety higher up and were eventually airlifted out.

The couple said they sprinted up a set of steps trying to reach higher elevations.

"Along the way, you know, houses were coming down, it was bringing down homes," Venkatesan said.

Raja said she could hear the screams of people who were being swept away by the floodwaters below.

A guide led them up to a flat area at the top of a nearby mountain. The climb was treacherous.

"So tall up, I don't know even how we climbed," Raja said. "It was really hard."