Abstract: A telephone line installer with 13 years of experience received a radio call from another telephone line installer to help install a telephone service drop. The first employee, who normally worked out of a van, got an aerial lift truck and drove to the work site. (The employee's supervisor was unaware that the employee was going to use an aerial lift.) The employee went up in the aerial lift bucket twice, pulling the telephone line thru a tree and cutting limbs off the tree as necessary. He went up for a third time, but did not use his safety belt, which was secured to the bucket. As the employee leaned out of the bucket to remove a limb, the bucket door, against which he was leaning, opened. He fell through the tree to the ground. He was hospitalized with fractured ribs.