The U.S. Navy has had some recent and terrible accidents that, from my perspective, are hard to understand, especially the collision of two war ships with merchant ships.
See this article, The most important lessons the Navy has learned from two deadly collisions. Again, the finger is pointed toward culture within an organization. I've thought often about the operations tempo that the United States military has sustained since 9/11, and as noted in the article, it is not sustained without consequences. The issue of "speaking truth to power" will always be an issue and not easily overcome. In the military, you don't want be labeled as a "nay-sayer and an eyeball roller."
Many a promising military career has ended due to those events. The Seventh Fleet commander was relieved (Navy speak: was dismissed) of his command, the ship captains likewise have had their careers sunk.
Are these lessons learned by the Navy or only "lessons observed?"