"a day that I'm sure no one involved ever forgot"

You can put out a fire by covering it with sand. Unless your fire involves something that can burn sand. In this great post about chlorine trifluoride in Derek Lowe's "things I won't work with" series, we read, "one commenter mentioned the utility of the good old sand bucket, and wondered if there was anything that would go on to set the sand on fire. Thanks to a note from reader Robert L., I can report that there is indeed such a reagent: chlorine trifluoride." Do read the whole thing, and don't miss the (PDF) Air Products Safetygram about the stuff, which includes the gem "one eyewitness described the incident by stating, 'the concrete was on fire!'"