As employers across the country observe National Trench Safety Stand Down Week from June 15–19, Cal/OSHA is calling on employers statewide to review trench safety requirements and reinforce jobsite protections to eliminate preventable cave-in incidents.
Sponsored annually by the National Utility Contractors Association (NUCA), the nationwide NSSD campaign serves as a critical reminder that trenching and excavation work remains among the most hazardous construction operations. A single cubic yard of soil can weigh as much as a car, making proper shoring, sloping, and shielding essential safety practices.
June is recognized nationally as Trench Safety Month, an annual campaign dedicated to raising awareness of trenching and excavation hazards and promoting safe work practices across the construction industry.
As part of this effort, Trench Safety Stand Down Week, encourages employers and workers to pause work activities to discuss trench safety, review hazard prevention measures, and reinforce the importance of protecting workers from cave-ins and other excavation-related hazards.
From 2021 through 2025, Cal/OSHA issued approximately 90 trench safety violations tied to worker injuries and fatalities. Currently, Cal/OSHA is investigating two Los Angeles County trench collapses that resulted in fatalities this year. Cal/OSHA enforces trench safety through penalties and criminal referrals while actively guiding employers to prevent future tragedies. Recent enforcement actions include:
– – Blackhawk Electric Company, San Diego; willful-serious and serious violations; $160,000 in proposed penalties. On December 3, 2025, the employer knowingly allowed their employees to work in a trench more than five feet high without protection from cave-ins.
– – W.E. O’Neill Construction Company of California, San Diego; willful-serious and serious violations; $160,000 in proposed penalties. On December 3, 2025, the employer knowingly allowed their employees to work in a trench more than five feet high without protection from cave-ins.
– – City of San Diego Public Utilities Department; willful-serious violations; $297,850 in proposed penalties. On December 1, 2025, two employees were working in a trench when the sides collapsed, causing injuries that required hospitalization.
– – Smelly Mel’s Plumbing and Sewer Rat Plumbing, South San Francisco; willful-serious, serious accident-related violations; $529,640 in fines combined. On August 1, 2024, a crew was handling a sewer-line project at a private residence; the walls of the trench collapsed, burying a worker and causing injuries that required hospitalization. Cal/OSHA’s Bureau of Investigations referred the case to the San Mateo District Attorney’s office, which has pressed felony charges.
What Cal/OSHA Chief Debra Lee said: “Trenching is one of the most dangerous jobs in construction, and employers are legally required to protect their workers. These recent citations highlight a troubling lack of compliance in the industry.”
A trench collapse is an avoidable tragedy. Fatalities and serious injuries continue to occur because employers fail to follow established trench safety requirements. Under Cal/OSHA regulations, employers are responsible for evaluating excavation hazards, including the potential for cave-ins, regardless of trench depth, and must implement appropriate protective measures to ensure worker safety.
For detailed trenching safety guidelines, review the “Excavation, Trenches, and Earthwork” chapter in Cal/OSHA’s Pocket Guide for the Construction Industry. Additional resources are available on NUCA’s Trench Safety Stand Down webpage.