(Photo: AP) Von Essen, who had served for six years as commissioner of the Fire Department of New York, directed the department's response to the attack, which claimed the lives of 343 firefighters. At the end of the Giuliani administration, he joined Giuliani's firm and serves as senior vice president. Since then, he has given speeches and written a memoir, "Strong of Heart." The book covered Von Essen's life as a firefighter, union president and finally commissioner, a tenure marked by contention over his efforts to change the tradition-bound department.