It's a interesting little footnote on history, when you bring up Mainz and the Powder Tower.
About five minutes walking from the University of Mainz.....heading toward the river....you will come to an area which was a military fort of sorts back two hundred years ago. Around some portion of it....was the powder magazine facility....where they stored kegs of primer for ammo.
Mainz had become a significant military fort during this mid-1800s period for the Bavarians, the Prussians and the Austrians to protect the nation from the 'evil French' (it's hard to say this without laughing but you must remember.....Germans were a different sort of people in the 1800s).
I should note....the 'evil French' from Napoleon's defeat on....were never able to win a battle against the mighty Prussians or Germans.
On 18 November 1857....in the mid-afternoon....the powder magazine exploded.
What is generally written down as fact....is that 57 houses were destroyed and another sixty-odd homes were heavily damaged. Even the windows of the Mainz Cathedral and Quintinskirch were destroyed.....which lay over a mile away from the site.
Local reports indicate that at least 150 Mainz folks were killed and roughly 500 were injured to some degree.
What is an odd feature about this accidental explosion is that a major event had been planned for that afternoon with Bavaria's Grand Duke Ludwig III, Nassau's (Hessen) Duke Adolf I, and the local Landgrave Ferdinand von Hesse-Homburg in attendance. For some unexplained reason.....at the last minute (prior to the explosion)....the entire festival was cancelled. The three gentlemen would have been fairly close to the affected area, and likely would have died in the explosion.
The cause? No one has ever said with any clarity. There is some belief of intention (maybe an act of revenge), and it's possible that someone was smoking near the munitions site. This is in the month of November and it's possible that someone started some fire to get warm and didn't realize what they were doing.
Oddly, what is generally recorded after the explosion.....massive tourism occurred with Germans coming from miles and miles away.....to see the site. This apparently went on for months, until everyone got their fill of the explosion event. The local military, seeing some positive out of tourism.....roped off the area and allowed tourists to roam through the affected area. No one says much of guided tours but I would imagine various military officers came around and did the guided tours....talking up what we'd consider 'Hartz-IV' type entertainment for the German masses.
Remember....in the mid-1800s....around the Mainz region....there just wasn't much to get excited about or entertained by except these occasional fests where beer would flow and circus-like acts would perform.
So, if you were walking around in the part of Mainz....there is a memorial of sorts....minor in nature to those who died on that fateful day. Mainz residents knowing the incident? I think if you questioned a thousand of them....less than ten would have some knowledge of the explosion.