FDNY Response Increased Mobilization

 Immediately after the second plane hit, the FDNY Chief of Department called a second fifth alarm.¹⁰¹

By 9:15, the number of FDNY personnel en route to or present at the scene was far greater than the commanding chiefs at the scene had requested. Five factors account for this disparity. First, while the second fifth alarm had called for 20 engine and 8 ladder companies, in fact 23 engine and 13 ladder companies were dispatched. Second, several other units self-dispatched. Third, because the attacks came so close to the 9:00 shift change, many firefighters just going off duty were given permission by company officers to "ride heavy" and became part of those on-duty teams, under the leadership of that unit's officer. Fourth, many off-duty firefighters responded from firehouses separately from the on-duty unit (in some cases when expressly told not to) or from home. The arrival of personnel in excess of that dispatched was particularly pronounced in the department's elite units. Fifth, numerous additional FDNY personnel-such as fire marshals and firefighters in administrative positions-who lacked a predetermined operating role also reported to the WTC.¹⁰²