The race to save hundreds in Nepal's hydropower tunnels

Nepal has a booming hydro-electric power industry with workers toiling away in underground tunnels at multiple sites. Around 900 of these workers are believed to be trapped since the torrent of water, mud and debris tore through the border area of Nepal and Tibet. There's hope that some of them could still be alive and there's a desperate effort to reach them, complicated by mud and damage to roads.