About: http://webisa.webdatacommons.org/117940813

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	Abandoned mines are not ventilated and pockets of methane, carbon dioxide and other deadly gases can form or simply displace oxygen, with no visible sign.
http://www.w3.org/ns/prov#wasQuotedFrom	blm.gov