The San Francisco District Attorney’s Office announced the charges Monday. Romero, an Alameda County resident who worked for D’Arcy & Harty Construction Inc., was on a sewer-upgrade project for the San Francisco Public Utilities Commission on Sept. 28, 2023, when the excavation gave way. Prosecutors say he was trapped beneath about 8 feet of dirt after a vehicle drove past.

The trench was about 2.5 feet wide, 5 feet long and 8 feet deep. Prosecutors allege it lacked proper support: the short sides were entirely unsupported, while the longer sides were only partly supported. A state workplace-safety inspector who investigated the death also concluded the excavation was not properly supported, according to prosecutors.

The defendants are company site safety representative John Darcy, 62; project manager John Tobin, 39; and crew foreman Filiberto Poblano Perez, 52, who directly supervised Romero. The San Francisco residents Darcy and Tobin and Richmond resident Poblano Perez, along with D’Arcy & Harty Construction Inc., face allegations including involuntary manslaughter and workplace-safety violations. All four defendants have pleaded not guilty.

Prosecutors also say the company had been the subject of a safety complaint about an inadequately supported trench at a different project less than three weeks before Romero’s death. The charges put the company’s and supervisors’ alleged safety decisions under scrutiny as the criminal case proceeds.