Note: This was written for the thread : Explosives are fun - stories? Most of the Seattle Boeing plants, particulary the old ones reside in King County, WA. I was the Lt. incharge of the King County Sheriff's Department Bomb Disposal unit, among other things. It seems the Boeing Company, hired a new safety director. He decided to check all of the many chemical labs and chemical storage areas within the Boeing plant system. He found many cases, of poor storage and/or cases of chemicals left over the years, when they should have been destroyed, etc. Picric Acid, being one of the most common. This chemical form salts, around metal caps, etc. that become sensitive to heat shock and friction and can explode. In most cases this was fairly easy to dispose of, since they were usually in quart cans. This chemical was used in a lot of Japanese munitions in WW II. We had already handled many Japanese grenades and knee mortar rounds containing this chemical. http://physchem.ox.ac.uk/MSDS/PI/picric_acid.html He did; however; much to our horror, find a 55 gallon drum of Tetrahydofuran, that had been sitting around untouched in the lab in Plant #2 since WW II. We didn't know much about that particular chemical, as well as a lot of the others we had to deal with. http://www.basf.com/diols/pdfs/tetrahy.pdf So we looked it up, it seems that Tetrahydofuran has some strict storage requirements that were not followed. The drum had been opened; however, just sat where it was over the years since WW II until the mid 80's. I was also advised that flumes or salts can form in the this chemical, if not stored or handled right and could become explosive. These flumes, if jarred could collide with each other causing an explosion. Given the amount of tetrahydofuran we were dealing with we were very concerned. This area is in a highly populated area. So we carefully loaded the drum into our Bomb Disposal trailer and with a convoy, transported it to our local County garbage disposal pit, which we normally used for explosive disposals. We decided to place a 1/2 pound of C-4 on the top and a 1/2 Pound on the bottom of the drum. We also hooked up a ring main with Det cord. We hooked it all up to fire electrically. The weather was overcast and we knew this would cause some problems; however, we wanted to get rid of the stuff. It was also night time. We cranked the charge off! Wow! First a cone sized flash engulfed the whole area, then the loudest boom that I have ever heard, followed by a mushroom cloud that looked like an Atomic Bomb blast! Of course the blast hit the overcast and bounced up and down through the valley breaking windows and cracking cement driveways! The local 911 board lit up with calls! My crew and I were still standing there with mouths agast! It was and is the largest detonation that the unit ever did.