Ouch!
Reminds me of my worst incident with a classic 12.5” f/10 Newtonian. We installed a new secondary in the scope and for some reason it cut loose from its mount with the tube pointing nearly straight up. Yes, it fell 10 feet onto the edge of the primary and shattered, taking a huge clam out of the back of the mirror. The front didn’t look bad, but strain release ruined the mirror. Fortunately, we had a twin of the antique 12.5” green Pyrex mirror blank and I fabricated a nearly exact replacement mirror, hitting the original focal length within 1/2” of the original. It’s one of the best mirrors that I have ever made and it is still catching starlight.
Ugh. Safety tip… don’t do that again!