The Uniformed Fire Officers Association says problems with the city's faulty 911 processing system caused a dispatch error during the fatal Spuyten-Duyvil train derailment.
The union claims the error mistakenly sent eight fire trucks to a small apartment building and not the site of the derailment.
Four people died as a result of the crash.
The Uniformed Fire Officers Association issued a statement saying that dispatch errors have become too common since the city declared in 2009 that 911 operators, not fire dispatchers, would handle fire calls.
The statement also said that sending eight units to Palisade Avenue meant that the trucks from Engine 52 and Ladder 52 didn't get to the right place until seven minutes after the 911 call.
Mayor Bill de Blasio brought a $2.1 million system update to a halt earlier this week.