Abstract: On September 22, 1994, Employee #1, of John Mournier Construction, Inc., was working on a new subdivision in Antelope, CA. Employee #1 and another carpenter were placing plywood siding on the second floor level of a two-story house. They were on ladders about 4 to 5 ft apart, carrying the plywood sheet between them. Employee #1's grip on the plywood sheet slipped, and when he regrabbed the plywood sheet, it caused stress and pain in his stomach. He was unable to continue to work and reported the incident to his foreman, after which he was taken to the Mercy San Juan Hospital, Sacramento, CA. He underwent exploratory surgery for an umbilical hernia and spent three days in the hospital.