Source: http://www.thebolditalic.com/articles/40...

In the early ’90s my friends and I used to tape flashlights to the handlebars of our bikes and go riding around in underground storm drain tunnels. There was a whole network of these tunnels under the city that sat empty for most of the year. We would go for miles snaking up and down the sides of the tubes, clapping and yelling to see how far our echoes would carry, eventually popping out in some other part of the city covered in cobwebs and bat guano. When the tubes got too small, we laid down on skateboards and kept going. If we found a flooded part, we taped garbage bags around our legs and crossed our fingers.