On September 11, 2001, the twin towers of the World Trade Center (WTC) in New York City were attacked by two hijacked commercial airplanes and subsequently collapsed. This heinous act of terrorism resulted in the deaths of 2,753 individuals, including 343 New York City firefighters who responded to the disaster., In this issue of CHEST, Aldrich et al report the results of a 13-year longitudinal study of spirometry results among 10,641 surviving firefighters with known smoking and body weight histories who were exposed to aerosolized dust following the collapse of the twin towers. This dust contained a highly toxic combination of pulverized building materials and chemical by-products of combustion and pyrolysis. The report published in this issue is a follow-up to two previous reports on lung function among firefighters at 1 year and 7 years following exposure to WTC dust., As such, it is the longest and most comprehensive study of longitudinal spirometry data among rescue and recovery workers who were exposed to toxic material during the response to a major environmental disaster. The results of this study are therefore extremely important for understanding the long-term effects of inhaling toxic aerosolized dust on lung function. Just as importantly, it is also the first study to report the effects of smoking and smoking cessation on longitudinal lung function decline caused by toxic exposures during a major environmental disaster.