Abstract: At approximately 10:21 a.m. on February 7, 2009, Employee #1 was working for Tremco, Inc., a manufacturer, distributor and installer of waterproofing materials. Workers from Tremco, Inc. were working with workers from Reliable Roofing and Sheet Metal, LLC, inspecting the water damage to the roof of a building. Reliable rented a Grove Aerial Lift, Model Number A125J. The Reliable Roofing foreman moved the lift into position to place it into operation. Two of the wheels were on the sidewalk, and two of the wheels were in the street. The wheels on the street were on a stack of three 1.75-in. thick boards. The Reliable foreman operated the lift from the basket, with Employee #1 riding in the basket. The operator moved the boom to reposition it to access a lower level of the roof. The operator had not been trained in the proper procedures for operating this machine. He lowered the lower riser while the other boom sections of the lift were still telescoped out. The sensors that should have presented this maneuver did not function. Another limit switch should have prevented the operator from lowering below a 72 degree angle with the boom extended, but it also malfunctioned. The operator lowered to an angle of 55 degrees, whereupon the machine exceeded its tipping moment. As it fell, the machine's man basket struck the corner of a neighboring building. Half of the basket was sheared off and the operator was thrown to the second story rooftop. The rest of the basket and Employee #1 were thrown into a fire door leading to the fire escape of the fourth floor of the neighboring building. Both workers were transported to Massachusetts General Hospital for treatment. Employee #1 died. The operator of the lift had never received specific formal training for the lift that he had been operating that day, and did not know its operational limitations. He did not perform any preoperation checks or inspections which would have identified the malfunctioning switches.