When I showed up to clean a customer’s windows, they requested I also clean a glass panel to their staircase similar to the one in this picture. They called back the next day to inform me the panel had fallen out of the clamps which secured it after I had left, and it shattered. They asked if I used any unnecessary pressure or a new technique for cleaning it that could have caused it to fall, and I informed them I had just used a traditional mop and squeegee method, with no extra scrubbing or pressure.
Apparently the clamps on the top and bottom of the panel that secure the glass in place did not have a bolt going through the pane, just a rubber gasket which held the pane in place by friction. As the bottom of the pane is angled, and the clamps are at different heights, there is both downward and lateral force on the clamps at all times. My guess is the soapy water coming into contact with the rubber gasket reduced the friction, and allowed the pane to slip sideways through the clamps. I just wanted to share my experience with you all in case you are asked to clean something similar. This design of securing panels this size and weight with compression clamps alone is very dangerous, as mere contact with a liquid can cause the whole panel to fall, so I would be very careful agreeing to clean something like this in the future.