Abstract: Employees #1, #2, #3, and #4 were installing vinyl siding on a three-story residential house from a wood pump jack scaffold, consisting of four doubled 40 ft long, 2 by 4 wood poles and three 20 ft aluminum platforms 33 ft 4 in. from the ground. One worker was on the ground. Each employee was assigned to work around each pole. When the four of them congregated around one pole, the pole broke and Employees #1, #2, #3, and #4 fell to the ground. Employee #1 suffered multiple arm fractures; Employee #2 suffered a fractured leg; Employee #3 suffered a cut/laceration on his leg; and Employee #4 sustained a cut/laceration on his foot/ankle. They were all hospitalized.