An employee was pulling a truck from a loading dock but could not get enough traction under the tires due to ice. After pulling the truck forward approximately 2 feet, the employee exited the vehicle to retrieve ice melt located in the rear of the trailer. The employee then dropped the bag of ice melt to the ground behind the trailer and was standing at ground level between the trailer and the loading dock. The airbag in the rear tag axle of the trailer engaged, lifting the rear axle up off the ground. The truck rolled backward, pinning him against the building. The employee was hospitalized with multiple pelvic fractures and a crushing injury to the abdomen and lower back, which required multiple surgeries.