The Oakland-based contractor whose worker was struck and killed by a steel beam in the Twin Peaks Tunnel seismic retrofit project has been tied to 11 prior accidents, and nearly 50 worker safety violations in the last decade. That’s what NBC Bay Area review of inspection records found for Shimmick Construction.

The accident, last Friday, claimed the life of 51-year-old Patrick Ricketts of Williams, a signal technician on the Twin Peaks project.

According to city officials, a steel beam fell