Witnesses said that they saw one of wings of the glider "dip" shortly after it was released from the tow plane. The glider then stalled and "nose dived" into the field.
No other details of the accident. The initial accident report from the FAA indicates that the aircraft was a PLZ Bielsko SZD55 glider of "pending" registration. It is classified as an "Experimental" aircraft in the "Racing" category.

The preliminary report is now available on ntsb page. Has a little clearer description of events. Horrible and unneeded loss.