U.S. and international rescue teams are hopeful they will find survivors as they work long hours searching through the rubble of a beachfront condo building in Surfside, Fla. It's been nearly a week since part of the 12-story structure collapsed in the middle of the night. Sixteen people are confirmed dead and 147 more are unaccounted for. Leon Roy Hausmann is a board member of Cadena International, a disaster assistance nonprofit that has provided a trained team of volunteers from Mexico to help with the search and rescue. "You detect life if you're lucky, and then you have the challenge to reach such location and take out the person, the survivor, you know, without harming him," Hausmann said in an interview with NPR's Morning Edition. "This is very treacherous terrain. It's not stable. It's challenging because you have to be very careful in the way that you reach without making the whole thing collapse," he said.Hausmann described the volunteers on the Cadena team "as young individuals, some of them are in the 20s. They left everything they were doing just to come here and help. But they're fully committed to fulfill this mission and find lives. And I cannot be more proud of them. They're amazing people."Their team also includes a rescue dog and a special device that uses sonar to spot underground movement. It can even register vital signs of possible survivors up to 39 feet beneath the rubble.Hausmann is Jewish and so are the seven men and women doing the dangerous work. He says a precept from the Talmud keeps him and his team going: Whoever saves one life saves the entire world."Of course, we want to save as many lives as we can, but even saving one life — to rescue somebody with life at this moment will be such a blessing," he said.He said that rescue teams from Cadena have worked in the aftermath of earthquakes, hurricanes and other humanitarian crises around the world. That included rescuing a survivor in Nepal who had been buried under rubble for seven days."Those are miracles," Hausmann said. "I don't want to create false expectations, but all I'm trying to say is that we still remain hopeful because that's who we are." Copyright 2021 NPR. To see more, visit https://www.npr.org.