Abstract: At approximately 9:15 a.m. on October 14, 2004, Employee #1, a foreman at a construction site, and a project manager were attempting to install a BT-S solid strut static thumb on a Caterpillar crawler backhoe, Model Number 315 CL. The static thumb is used to hold big loads in place that do not fit in the bucket of the backhoe or overflow the bucket and weighs approximately 500 lbs. Specifically, the thumb is used to secure large rocks in place in the bucket. Initially, they tried to align the holes on the static thumb with the holes on the backhoe and insert a securing pin, but were unsuccessful. Employee #1 then climbed up onto the left side of the bucket and tried to line the holes up on the static thumb, but the holes would still not line up for the pin to be pushed through. The holes were greased to try and make it easier for installation, and Employee #1 stepped across the front of the bucket to access its right side. He slipped and grabbed the unsecured static thumb with both hands. The weight of Employee #1 caused the static thumb to close on him. Employee #1 was pinned by his upper chest between the bucket and its teeth. Employee #1 was transported to a local shock trauma unit, where he was hospitalized and treated for a compression fracture to his T-3 vertebrae, chipped five additional vertebrae, a broken rib, punctured lung, and a blood clot in his chest. During the accident investigation it was revealed that there was not written procedure on how to secure the static thumb and no training had been provided.