Abstract: At or about 8:30 a.m. on December 23, 1991, Employee #1, of Ontario-Montclair School District, was trimming a tree from atop an 8 ft portable wooden stepladder. The ladder was placed on an uneven lawn that was wet due to sprinkler irrigation and dew. Employee #1's foot slipped from the stepladder and he fell backward, seriously injuring his back. Employee #1 was transported to Ontario Community Hospital and later transferred to Loma Linda University Medical Center for treatment. Employee #1 was a volunteer and a substitute custodian. He said that he had come to the school because the head custodian had asked him if he would trim the lower branches of trees. When Employee #1 arrived, he took the keys from the head custodian to unlock the store room to take the stepladder and a four-wheel cart. The head custodian showed him the branches to be cut and she worked with him for 15 to 20 minutes, cleaning the cut branches and holding the stepladder. Then she left the site to do other work.