The deaths of firefighters Joseph P. Graffagnino and Robert Beddia at the Deutsche Bank building at Ground Zero in 2007 needlessly replayed in miniature the tragedy that unfolded on Sept. 11, 2001, when 343 of New York's Bravest died. The high-rise bank building, adjacent to the World Trade Center, was damaged in the attack and, six years later, was being cleaned of asbestos and demolished.

State Supreme Court Judge Rena Uviller and a jury in Manhattan now are deciding whether to convict three contractor site supervisors as well as subcontracting firm John Galt Corp. on criminal charges in connection with the fatalities.

The defendants made dangerous mistakes and were careless about fire safety. Civil financial damages against them may rightfully pile as high as a New York City skyscraper. But no one committed manslaughter, and no one should be convicted of it.

Although there were many poor practices at the site, the evidence shows that the prosecutors and the grand jury acted out of emotion rather than a clear sense of justice in charging Mitchel Alvo and Salvatore DePaola, both employed by John Galt Corp., the asbestos-abatement subcontractor, and Jeffrey Melofchik, who worked for Bovis Lend Lease, the construction manager.

Manslaughter statutes are effective against drunk drivers or those who shoot guns in populated areas. As a rule, the causes of workplace accidents are too complex and difficult for most prosecutors to explain to juries and judges.

One argument for acquittal is that the long series of events involved in the deaths—asbestos abatement in work areas under negative-air containment; a standpipe cut to speed work, depriving the sprinkler system and firefighters of water; a lighted cigarette thrown away by a worker, igniting debris; spreading fire and smoke; disoriented firefighters extending their time in the building as their air supply ran out—could not have been reasonably anticipated by the site supervisors.

Another reason is that the circumstances of the firefighters' deaths from smoke inhalation suggest there were numerous random factors and decisions that affected the outcome. The firefighters who died were not attempting to rescue any construction workers who they believed were trapped, according to a federal report released last year. They were on a hose crew attempting to get water onto the source of the fire in a confusing physical setting.

New York City jobsites may well be safer because of this trial, but there is no straight line from the defendants' actions to the firefighters' deaths. The prosecution is concentrating the weight of the tragedy on the heads of these three men when, in fact, their respective roles were circumscribed and only a part of a long, complicated sequence of events. If not decency, fairness demands individuals not be convicted wrongly just to frighten the construction industry into running safer jobsites.