On Saturday, August 22, a group of cavers visited Grapevine Pit, an entrance to Lost World Caverns, a commercial cave in Greenbrier County, West Virginia. This is a 120-foot free drop that is cemented over at the top, leaving a 15-inch square hole with a gate. Under the cement is a jam of rotting logs; several years ago they cleaned this by knocking down all the logs they could reach.
George Dasher was ascending in a ropewalker and reached the hole at the top. He reached out a foot to get a hold and struggled a bit, trying to get through the small opening. When his foot touched one of the logs, it fell. He yelled "Rock!" twice, watching the log spinning end-over-end into the darkness. Susanna Clark was below, giving tension on the rope, and she dashed down the tour stairs off one side at the bottom. The ten foot by four to five inch log struck and damaged the 2x4 guardrail of a tour platform but missed Clark.
NSS News, December 1993 (Part 2) V51N12, Page 364-365.
George Dasher "Incident at Grapevine" unplublished report, August 26, 1992, 2 pages.
George Dasher "Rockin' Chair" The West Virginia Caver 10:5 October, 1992, p 11.
Giving tension or bottom belays is often dangerous. Whatever vertical system you use, practice it until you require no aid.