Abstract: Employee #1 and a coworker were replacing broken end posts in a vineyard. Employee was working in front of a post driver at the north end of block 174. The main post was driven down 4.5 ft, extra post section put into driver to allow main post to be driven down to 1 ft above ground. Employee #1 was using a 3-ft-long tool to hold an extra post into position. Employee #1 was standing in front of the open sides of the driver frame of a Fiat 80-75 agricultural crawler tractor with shaver HD-12 hydraulic posts drivers mounted on the right front of the tractor). Employee #1 suffered a fatal skull fracture when he was hit in the head above the left eye with a 53.5-in by 4-in post.