Redwoods are some of the most stable trees in the World. That is partly why they can survive for thousands of years. In my entire career, I have seen very few fall, and only inspected two.
Of those two, one fell because it had co-dominant leaders (double trunks) that fell away from each other, which is more of a structural deficiency than instability. The other, which I suspect was demonically possessed, was a small tree less than thirty feet tall, that literally jumped up out of the ground and onto an Astro van more than ten feet away. A rare ‘updraft’ was blamed.
Almost all of the redwoods here regenerated from the stumps and roots of much older trees that were clear cut harvested a century or so ago. Most of those that grew back with structurally deficient co-dominant leaders are very effectively sheltered from wind by their collective groves. Roots systems are very extensive, very resilient, and too intermeshed to be compromised.
The trunks in the picture above are part of a group of several trunks that grew from roots of the same tree that has been gone for a very long time. All are genetically identical and very close together. They happen to be a focal point of a big patio at a conference center. Although the structural integrity of the limbs within their canopy is a concern, the stability of the trunks is not.
Regardless, I am impressed by their attempt to improve stability. The limb that extends horizontally across the middle of this picture from the trunk to the left grafted to the trunk to the right! It is not uncommon for crossing limbs and trunks to rub through their bark to expose the cambium, but how do they stay still long enough to graft together?!