Abstract: At 12:15 p.m. on July 28, 2020, Employee #1, employed by Creative Assembly Inc., was performing concrete formwork at a site for JS Sullivan Development in San Francisco, CA. While assisting other employees in getting tools on level 7, the floor collapsed underneath him, causing him to fall to level 6. The San Francisco Fire Department reported the incident at approximately 4:02 p.m., and the employer followed up with a report at 7:08 p.m. The employee sustained eight broken ribs, a fractured back, and a knee injury. He was hospitalized for five days. An investigation was opened by the Compliance Safety and Health Officer (CSHO) on July 31, 2020. The primary causal factor in this incident was the lack of proper marking and securing of the area during formwork removal, which was intended for a stairwell opening. No accident-related citations were issued regarding Title 8 violations, although two citations were issued for other reasons.