Millions of tourists walk up and down the Las Vegas strip every year, looking to have fun and make some money. But beneath the flashing lights, there is a much darker side of Las Vegas.
Underneath Sin City's most famous casinos is a secret world: a labyrinth of tunnels that run for miles under the Las Vegas Valley. Built to protect the desert city from flash floods, the tunnels have become home to hundreds of Las Vegas' homeless.
Nightline visited the underground world beneath the Las Vegas...Full Story