About: http://webisa.webdatacommons.org/213341520

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	Video cameras can be placed through a borehole to view the void, but lighting is a problem and the images are poor, he noted.
http://www.w3.org/ns/prov#wasQuotedFrom	post-gazette.com