An Oakland, California structure collapse that sent 13 workers to the hospital will cost three contractors $147,315 in penalties, according to Cal/OSHA.

The incident occurred on May 26, 2017 and involved a temporary mold (formwork) and vertical shoring. Workers at the 435-unit mixed-use project construction site were pouring concrete into elevated formwork when the shoring system supporting the formwork collapsed. The workers fell some 20 feet, along with freshly poured concrete, reinforcing steel, timber framework, and tools and equipment. One worker’s injuries required surgery.

“Significant safety lapses caused injuries that could have been much worse if the workers hadn’t landed in freshly poured concrete,” said Cal/OSHA Chief Juliann Sum. “Employers must identify, evaluate and correct unsafe working conditions and follow all requirements to prevent employee injuries and illnesses.”

Cal/OSHA’s investigation found that the formwork and vertical shoring system that collapsed were not properly designed, installed or inspected. Cal/OSHA issued serious and serious accident-related citations to subcontractors Largo Concrete, Inc. and N.M.N. Construction, Inc. for $73,365 and $70,320, respectively, for failure to ensure that the formwork and vertical shoring were designed to safely withstand all intended loads, failure to have calculations and drawings approved by a California registered civil engineer as required for vertical shoring over 14 feet tall, and failure to ensure the shoring supports were erected on a level and stable base. General citations were issued to general contractor Johnstone Moyer, Inc. for $3,630 in proposed penalties.