In terms of legal issues and regulatory compliance, what makes compensation for workers at the 9/11/01 World Trade Center site difficult?

OSHA laws were suspended during the World Trade Center disaster and cleanup effort, so workers' safety was not guaranteed.

Many of the workers have since moved to other states and cannot be traced.

No one at the time kept records of the people working at the World Trade Center site.

It is difficult to prove that a worker's illness or death was directly caused by conditions at the World Trade Center site.