Manhattan District Attorney Robert M. Morgenthau said attorneys in his office have been in touch with city fire marshals to determine whether criminal violations occurred in Saturday's fire at the former Deutsche Bank office building next to the World Trade Center site.
Authorities said it was not unusual for prosecutors to join the investigation of a serious building fire or collapse. Their involvement would give fire marshals subpoena power, should they need it.
The cause of the blaze, in which two firefighters died on the building's 14th floor, was still under investigation.
"The public deserves it, the fire department deserves to know the truth," Steve Cassidy of the Uniformed Firefighters Association told CBS News correspondent Kelly Wallace.
City officials have said that the fire started on the 17th floor of a building that was being dismantled floor by floor. Workers were cleaning asbestos and other materials on that and several other floors on Saturday afternoon when the fire broke out.
According to documents obtained by CBS News, the John Galt Corporation, the chief subcontractor in charge of asbestos removal from the building, was slapped with nearly 20 serious citations for construction hazards as recently as June and July of 2007, reports Wallace.
The New York Post quoted an unidentified law enforcement official as saying: "We know the water didn't work. So you have to figure out whether they (the contractors) were negligent. If they are, they could possibly face under the law a form of criminally negligent homicide."
Mayor Michael Bloomberg said earlier Tuesday that the investigation was continuing and "at this point, there's no reason for anybody to think in terms of criminal charges or anything else."
City officials have said that workers would routinely take smoking breaks near the place where the fire started, and that electrical equipment including hot water heaters for decontamination showers were also nearby.
Investigators said Monday that a piece of the standpipe system, which connects fire hoses from the outside to a water supply line for the building, was found unattached and lying on the basement floor.
As details emerged about the flaws in the system, fire safety experts questioned why more thorough tests weren't conducted, and one person involved in the project says the problem may have existed for more than a year.
City Department of Buildings officials said they had manually tested the standpipe on each floor of the building — originally a 41-story tower that had been demolished to the 26th floor — before taking it down.
But it wasn't clear if or when officials had filled the dry system with water to test the pressure of the complete system.
Fire safety expert Glenn Corbett said that would have been the "only way to test the integrity of the system" and that more testing should have been done.