I posted a video of this formation earlier. It was hard when I touched it. This tunnel has a smell of petroleum and signs of asphalt seepage or something similar. I've never experienced it in any tunnel before probably because this is the oldest I've been in to date (1914). There are older tunnels, however but certain factors still need to occur in order create the formations found in this tunnel. I have to say that coming across weird things like this is one of the reasons why I enjoy BelowLA. We are in an alien environment finding things unusual to the world above. PLEASE SUBSCRIBE TO MY GROWING YOUTUBE CHANNEL!!! ______________________________________________________________________ @danonewillrise297 @christian.healy ______________________________________________________________________ #BelowLA #BelowLosAngeles #LAriver #losangelesriver #draining #westLA #LArain #raininLA #ballonacreek #losangeles #california #westlosangeles #lacounty #calilife #calilove #flood #pollution #culvercity #stormdrain #floodcontrol #floodprevention #river #sanfernandovalley #civilengineer #sanitation #civilengineering #urbex #hydrology #ladpw #ladwp (at Los Angeles, California) https://www.instagram.com/p/CNnfvTKAQAd/?igshid=2qyfnvql8996