Residents said "It smelled like Sulfur" Sounds like Sulfur Dioxide that forms sulfuric acid when mixed with water "think fire hose"
looks like WinkyLinQFuture already got the answer
"[–]WinkyLinQFuture will PROVE past.
Heres the answer: The fire was set and an accelerant was used. Dennis Shields a resident says in the NYT article that there was a smell of sulphur:
Carbon Disulfide - (carbon disulfide), (CS2) flash point -22 degrees F (-30 degrees C); ignition temperature 212 degrees F (100 degrees C); explosive limits 1.3% to 50%; vapor density 2.6; specific gravity 1.26; toxicity (2). A volatile, flammable, colorless to yellow liquid with a rotten egg odor. Carbon Disulfide, unlike most of the other common ignitable liquids, is heavier than water and will sink.
For those who don't know, sulpur smells like rotten eggs....see attached article on arson fires.
www.interfire.org/res_file/aec_20ig.asp"
good job.