Sources:
https://adventure.howstuffworks.com/outdoor-activities/urban-sports/10-urban-sports-arrested.htm
https://www.wonderslist.com/10-dangerous-sports/

Wingsuit Jumping: 
http://www.dailymail.co.uk/news/article-3184693/Officials-puzzled-Yosemite-jumpers-deaths.html

Train Surfing:
http://metro.co.uk/2017/09/20/teenager-suffers-ruptured-testicles-after-smashing-into-sign-while-train-surfing-6943845/
Drag Racing
https://www.theguardian.com/music/2014/jan/23/justin-bieber-arrested-drag-raciing-driving-influence-miami
http://www.nbcnews.com/id/23194752/ns/us_news-life/t/police-dead-crash-illegal-drag-race/
Urban Tightrope Walking:
http://www.telegraph.co.uk/film/the-walk/philippe_petit_world_trade_center/
Street Luging:
http://www.auldovertheroad.com/lugefaq.htm
http://www.clarkedailynews.com/police-break-up-illegal-street-luge-on-mt-weather/
Base Jumping:
https://adventure.howstuffworks.com/outdoor-activities/urban-sports/base-jumping3.htm