Abstract: At approximately 12:30 p.m. on December 01, 2021, an employee at the City of Vallejo Water Department was working at the Travis AFB Water Treatment Plant cleaning out a sedimentation basin inlet channel, approximately 5 ft deep, with a fire hose and hydrant. The employee accessed the basin by lifting about six grates that were 3 ft by 3 ft. The employee suddenly slipped and the metal around the grate crushed the employee's knee. At approximately 07:08 p.m. on December 01, 2021, DOSH was notified of the incident in compliance with T8CCR�342 and arrived on site to investigate on December 07, 2021. The employee was treated at David Grant Medical Center and then later transferred to Kaiser Vacaville for surgery of a crushed knee.