The reason I suggested Denko is because one response from the PORT AUTHORITY was that their paperwork was lost in the collapse. Maybe someone should ask Sergei? Sounds like a job for a professional journalist, but I can't find one.
Are you telling me that the property management office at the Port Authority was in the WTC? That just doesn't make sense (the office space in that building is too valuable). One would think that they would centralize their property maintenance operations elsewhere. Fire sprinkler maintenance requires special licenses and certs and the State should have records on those as well.
I smell a coverup; but I would bet that the records have been destroyed. That would indicate the need for a hard look at organizational responsibilities within the NYPA.