Abstract: At 9:55 a.m. on April 7, 2020, an employee was working in housekeeping at an elementary school. He was a custodian. He was standing on the tenth rung of a portable extension ladder. He was cleaning a windowsill. To clean the windowsill, he was using a Webster duster, which he was holding in his right hand. The ladder was positioned on a smooth tiled floor. The ladder was not being held by someone or otherwise secured from below. The footing of the ladder slipped, and the employee fell along with the ladder to grade. The fall distance was approximately 10 feet (3.1 meters). The employee suffered a 30 percent compression fracture of his fifth thoracic vertebra. According to one account, he was not hospitalized, but treated and discharged from the emergency department of a medical center within less than 24 hours. According to another account, he was hospitalized. This accident was not serious as classified by Title 8 CCR 330 (h) and confirmed by the CAL/OSHA medical unit. The employer did not ensure that an extension portable ladder was so placed as to prevent slipping, or that it was tied, blocked, held, or secured to prevent slipping.