Abstract: On June 2, 2012, Employee #1, employed by St. Francis Electric, Inc., San Leandro, CA, was working at the San Francisco Airport, San Francisco, CA. He was working on a new job assignment given him by his foreman, to operate a Davis Fleetline 70+4, also known as a Hydraulic Core Drill Machine or T-70 Davis Trencher. His task was to bore holes up to 34 inches deep and up to 30 inches in diameter into the airport runway surface. Runway lights were to be installed in these holes. At approximately 1:25 p.m., Employee #1 was informed by his foreman that the Hydraulic Core Drill Machine was leaking oil. The foreman instructed Employee #1 not to shut the machine down with the core bit on the ground, so Employee #1 started the machine up and raised the drill. Under the direction of the foreman, Employee #1 and the foreman began to search for the source of the leak. The foreman instructed Employee #1 that the Federal Aviation Administration (FAA) did not want oil on the runway and to get some rags to wipe up the oil. The foreman walked away. Employee #1 turned off the Hydraulic Core Drill Machine, acquired some rags, and wiped the oil that had spilled on the runway as well as the oil that had leaked onto the outer part of the machine. Employee #1 then turned the Hydraulic Core Drill Machine back on because, since it was hydraulic operated, it had to be turned on to see where the oil was leaking. Employee #1 noticed oil leaking from the hydraulic fittings on the outer parts of the machine. As he wiped the leaking oil from the coupling of the machine's exterior, a gust of wind blew the tail end of the rag that he held in his hand. The tail end of the rag caught in the unguarded belt and pulley drive system of the Hydraulic Core Drill Machine. This event happened in an instant, too quick for Employee #1 to be able to release the rag. The rag and the employee's hand were pulled onto the nip point of the unguarded moving belt and pulley drive system. The middle finger of Employee #1's left hand was mangled and amputated. The employee was hospitalized. The employer did not report this serious injury to Cal/OSHA within the required 24 hours.