NYC firefighter dies while battling blaze NEW YORK, April 17 (UPI) -- Officials say a New York City firefighter who had been at the World Trade Center disaster died of an apparent heart attack while battling a blaze Monday. Lt. Rich Nappi, 47, collapsed while knocking down a three-alarm fire in a commercial building in Brooklyn and died shortly after arrival at a nearby hospital. "Lt. Nappi overheated, suffered exhaustion and collapsed," Mayor Michael Bloomberg told reporters. He was rushed here to Woodhull Hospital, but despite the best efforts of medical personnel, he eventually died. Nappi was the first New York firefighter to die in the line of duty since 2009. He had been with the FDNY for 17 years and was one of the first on the scene of the Sept. 11, 2001, terror attack. "He responded with valor to the World Trade Center attacks," Bloomberg said. This is a tragic day for New York City. Nappi's colleagues at the Engine Co. 237 station in Brooklyn hung black and purple bunting over the doorway as a sign of mourning. "He was just a firefighter's firefighter," Lt. Tom Minelli told the New York Daily News. He loved being in the firehouse. He loved being a firefighter. Eight other firefighters were injured battling the same blaze at the building on Flushing Avenue that housed a restaurant-supply business and was packed with merchandise. Doctors suspect the sultry spring temperatures in New York added to the strain on Nappi's heart, the New York Post said Tuesday. "It was very hot, extremely hot, a lot of smoke," firefighter Ed Hiler told the Daily News. Time will tell us what happened.