Abstract: At 4:15 p.m. on September 16, 2004, Employee #1, a snack bar attendant who serves food at the snack bar of a bowling lane, was seriously injured when she tripped and fell. Prior to the accident, plumbing repairs were being made to a pipe under the kitchen floor. To cover a hole, the plumber and a mechanic working for the bowling lane put down a thin plywood board over the hole. On the morning of the accident, the head mechanic and supervisor removed the thinner board and replaced it with a 4-foot by 4-foot plywood board which was no more than 0.37 inches thick. This board was covered over by a mat 0.45 inches thick. The employees in the snack bar prepare food to be served at two counters next to the kitchen. Employee #1 arrived to work on the swing shift. She was told by another snack bar attendant about the rise in the kitchen floor due to the board. Employee #1 said she was standing at the front counter, walked down the kitchen aisle toward the office, and tripped and fell near the stove. Employee #1 said her toe caught the mat or the exposed wood on the side of the mat. She said she hit her elbow. The only other witness in the area was the cook and pizza maker. The employer and employees, except for Employee #1, said warning tape was placed on the floor around the plywood. Employee #1 fractured her left elbow and was hospitalized for seven days.