My boat has a bolt on keel, meaning the lead keel is attached to the rest of the boat via some pretty stout bolts.
If they are not in good condition, then this can happen
Pretty much an instant, unrecoverable capsize, which is fatal for both boat and crew.
So yeah, check your keel bolts.
This involved removing the nut from the bolt using a impact driver
Then cleaning the bolt/nut, checking for rust, and then using acetone to clean all around.
Then putting the washer back in place with a blob of sealant under it to stop bilge water getting into the keel/hull gap from the bilge, and then putting the nut back on
I then used a torque wrench to tighten to 132 ft/lbs
Should be good now for a while! Very relived to see all the bolts and nuts were in great condition, and there was no weeping on the outside of the hull, so I am assuming that the join is still watertight, and my keel will NOT in fact fall off. I hope.