Abstract: At 3:30 p.m. on April 5, 2019, an employee, an assembler, was assisting a coworker, a mechanical design engineer, in troubleshooting a belt loader truck, used at airports to load baggage onto planes, that had a squeaking fan belt of unknown cause. The employee crawled underneath the engine bay compartment to check the tension of the belt while the coworker was watching. After the employee moved away from the engine bay compartment, the coworker started the engine but the squeak was still present. The coworker instructed the employee to return to his original department because they would continue troubleshooting the truck the next day. However, the employee crawled back underneath the engine bay compartment to check on the belt tension once more by pressing on it with his right hand. The coworker, unaware that the employee was under the engine bay, started the engine. The employee heard the engine starting and removed himself quickly from underneath the engine bay. The employee felt his right hand become numb because his right index finger had been partially amputated by the engine's belt. The employee was hospitalized to treat a partial amputation of his right index finger.