Investigators say the explosion happened Wednesday while the people were using butane to extract the intoxicating chemical THC from the marijuana plant.
Links
[1] http://www.9news.com/story/news/local/9news-evenings/2014/04/23/explosion-marijuana-grow/8059633/
[2] http://rethinkpot.org/tags/colorado-0
[3] http://rethinkpot.org/tags/danger