Abstract: At 2:00 p.m. on November 1, 1990, Employee #1, who had 1 year of truck-tire-mounting experience, was inflating a Loops truck tire. The tire had a properly seated three-piece rim in a Ken Tool five-bar tire cage (Model No. T105). He was using a clip-on inflating chuck and 170-psi air supply, without an in-line pressure gauge or a presettable regulator. He was not using a spreader because one was not available. Although there was a witness to the contrary, Employee #1 stated that he did not leave the cage area while he took off the chuck, tested the tire at 45 psi with his pocket gauge, and put the chuck back on. He did not remember what happened after that. Shortly thereafter, the tire exploded, causing the cage to expand, jump, and strike Employee #1's head. He sustained a skull fracture and temporary loss of sight in one eye. He said that he was not familiar with truck tire mounting chains and rim manuals. Because the same tire and rim pieces were later mounted with a new tube and liner without incident, it appears that Employee #1 may not have had the rim pieces mounted properly.