http://www.sbsun.com/general-news/20160703/downed-paraglider-rescued-near-san-bernardino-airpark

Ken Howells, a hangglider and paraglider pilot who was at the airpark but did
not see the crash, surmised that turbulence in a thermal could have caused him
to go down. He said such a condition can cause a wingtip to fold under and the
paraglider to sink.

A pilot can maneuver out of it, he said, so long as there is sufficient
altitude.