The request by the Uniformed Fire Officers Association comes after a contractor was acquitted Wednesday of manslaughter and other charges in the 2007 fire at the former Deutsche Bank building.
The company he worked for was found guilty of a misdemeanor.
The union is asking Manhattan District Attorney Cyrus Vance Jr. to examine the role of the Lower Manhattan Development Corp., the city-state agency that owned the building.
Union head Alexander Hagan accused the LMDC of negligence in a letter to Vance on Thursday.
The district attorney's office had no comment. A spokesman for the LMDC did not immediately return a call seeking comment.
