Abstract: Near the end of the work day, Employees #1 through #3 and two coworkers were connecting a truck and a trailer, and loading it with miscellaneous equipment. Nearby, a foreman had parked a rubber-tired front end loader on the side of a sloped roadway. The loader was parked facing uphill, with the brakes set and engine shut off. After he left to retrieve a coworker from another area of the project, the loader rolled backward down the 8 to 10 degree sloped hill, striking the truck and trailer. Several of the employees were working between the truck and trailer to hook up the trailer to the hitch. Because of ambient noise from the truck's engine and from a nearby crew that was operating a backhoe, no one heard the loader rolling down toward them. Employee #1 became trapped under the differential assembly and was killed. Employees #2 and #3 sustained lacerations and possible fractures, for which Employee #2 was hospitalized. The other two coworkers were not injured. The parking brake was still set on the loader when it was later inspected.