I posted before on my own blooper before a Mass.
Well actually this wasn’t the most embarrassing thing that has ever happened to me at Church. Once before Mass I was praying at an altar rail before the Blessed Sacrament. Some time had passed and my legs fell asleep. When I got up I started to fall and grabbed the top of the altar rail to stabilize myself. The rail was covered in marble and where I grabbed wasn’t very secure since about a three foot section of marble came off and I fell backwards and had that section of altar rail laying on top of me. People made sure I was alright and pulled that section off of me.