Exploding Planchette

I have posted a few stories on this site and in my first, I clearly stated that I have had 4 distinct experiences. However, today as I was reading through some of the stories, an incident popped into my head that happened many, many moons ago when I was around 13 years old (it could have been earlier).

We, my sisters and I, were visiting my aunt and uncle in Belfast during the school holidays. My cousins N and her adopted sister D were quite a few years older than me, as was my one sister.

One day my cousin N and my older sister decided to visit D in her newly rented apartment. I'm not sure where this place was, it is just too long ago, but it was quite close to my aunt's house. I, of course, begged to be allowed to tag along.

While there N and D suggested that we try a home made Ouija board (we referred to it as mirror, mirror), they quickly set it up. It was a large round mirror with hand written alphabet placed around the outer edges of the mirror as well as the words yes and no.

As far as I can remember there were no prayers for protection but after explaining that we all had to put our fingers on an upside down shot glass, which would act as our planchette, N and D started asking questions.

We very soon started getting answers to the questions and then the blaming game started. "You're moving it" says D to N. "No, you're moving it" N replies, "no you are", "no you are" and we all burst out laughing. As soon as we started laughing, the shot glass shot straight up into the air above our heads and exploded, sending small glass fragments shooting in every direction possible. Needless to say, we all jumped to our feet and ran as if our lives depended on it.

I never went back to D's apartment. In fact, I never saw her again. A year or 2 later D married and moved away.

I am now 56 and only a few months ago, D and I reconnected.

This experience scared the c...p out of me and I have never again tried to play "mirror, mirror" even though I am very inquisitive, I just don't know enough to do this safely.

I would like to know your thoughts on why this could have happened.