Abstract: On May 27, 2007, Employee #1 and a coworker, both maintenance workers, were assembling a table roll for the 110-inch mill. They were using a gear puller and a Simplex 100-ton double-acting hydraulic cylinder (Model Number XR1006AD, Order Number 17133, Serial Number 217) to remove a housing from around a bearing. Employee #1 began applying pressure to the hydraulic ram, using a Power Team porta power unit (Model Number PE 554T, Serial Number 319259). Only one of the two required hydraulic hoses was properly attached to the double-acting hydraulic cylinder. One end of the hose was attached to the "B" port on the porta power unit, and the other end of the hose was attached to the end pressure port on the Simplex hydraulic cylinder. Prior to making contact with the bearing, and at an unknown pressure, the female end of the unused return port coupler (Enerpac Type CR40003994X hose coupler, rated for 10,000 psi) failed. Internal components, including a chrome steel ball that controls flow, were blown out. Employee #1 was standing approximately four feet in front of the coupler when it failed. He was killed when internal components released by the coupler's failure struck him in the chest.