In California, John Schueler, a former San Diego contractor and scaffold design expert who serves as a witness on behalf of both contractors and injured workers, agreed that most of the "grunt labor" in the construction industry is being done by undocumented workers.
"Accidents are on the rise because an increasing percentage of scaffolding workers are uneducated and don't get the training that OSHA demands," he said.
Contractors are not only cutting costs on labor, but on materials. Schueler said some shoddy scaffolding imported from China is to blame for some accidents.
"The Chinese are cutting corners," he said. "They know what the cost is, and we are open about our designs and they copy us. It's cheaper to buy from China, and the product looks just the same."
These short cuts, as well as paying lower worker wages -- even if it means the occasional worker's compensation payment -- is "just part of doing business," said Rosasco.
But the workers are the biggest victims.
"They fall one day, they are in a coma, the employer never visits them in the hospital and moves on to the next illegal worker," he said. "It's like replacing the widget in a factory."