It is never just one thing; it is a combination of errors.
If we can learn from other people's mistakes, it makes sense to do so. I recognize that often it is not possible, but given the opportunity to see what went wrong, we should pay attention and see if we can make applications to our own personal and professional lives.
Back when the U.S. Navy had two destroyers colliding with commercial ships, I wrote about what possibly could have gone wrong. It wasn't clear, but you can listen to this podcast How The Navy Failed Its Sailors to get some of the gist associated with the investigations that followed. In the podcast, there is more concentration on the first collision.
Like most disasters, and I'll call these collisions disasters, there is almost always more than one poor judgment made or a failure of a single piece of equipment. Similar to these Navy incidents, I expect there will be many lessons from the current Boeing 737 MAX investigations that are going on and the contributing elements to those two terrible aircraft crashes.
In the case of the Navy, I could not understand how a modern destroyer whose function is threat detection could be hit by a 30,000-ton commercial ship. What about the simple thing of watch officers stationed on each side of the ship with binoculars?
Listen to the podcast. There was defective equipment. There were ill-trained and inexperienced persons doing critical tasks — helmsmen for instance! There was a terrible error in judgment compounded by the fact that the first collision order given was correct, but not immediately followed. Then there was the Navy culture of "getting by" with fewer staff, inadequately maintained equipment, all in the mission of maintaining operations tempo for sailings.
We in emergency management are notorious for getting by with what we are provided. Senior political and appointed leaders don't want to spend the money to maintain a high level of operational proficiency and readiness. Thus, as I've written about just this year, we have all the warning failures that were documented in California. And likely in other places, but without the dramatic number of deaths associated with a fast-moving wildland fire disaster.
Generally speaking, I think we as a profession have much more in common with the United States Navy than many would assume.