Abstract: At approximately 9:30 a.m. on October 23, 2013, Employee #1 was working as a plumber for the California Department Corrections and Rehabilitation (CDCR) Division of Inmate Ward Labor. This employer was a construction entity of the State of California that constructed buildings for the prison facilities. He had been a plumber for 32 years, and he had worked at this location as an intermediate employee for 21 years. On the day of the incident, Employee #1 started work at 6:30 a.m. He drove to the job site and got his toolbox from the back of his truck. As he was walking to the job site with his toolbox in both hands he stepped into a hole in the ground. He twisted his right foot and felt pain from his knee down to his ankle. He continued to work. He didn't report the incident to his supervisor until approximately two hours later, when he started experiencing swelling. Employee #1 drove himself to the medical clinic. He was diagnosed as having a sprained knee, ankle, and foot. After two weeks of therapy, the workers' compensation doctor advised Employee #1 to see his regular personal doctor for high blood pressure. His personal doctor was able to see him that day and admitted him to the hospital immediately. Employee #1 was admitted to the hospital on November 6, 2012, and he was discharged on November 9, 2012. He was diagnosed with and treated for an acute venous thrombosis of the right lower extremity and hypertension. He reported the hospitalization to his employer on November 8, 2012. The employer immediately reported the incident to Cal/OSHA. At approximately 1:40 p.m. on November 8, 2012, the Cal/OSHA West Covina District office received the report.