In the case of Challenger, I think it's pretty clear this was the "root cause":

> According to testimony by Kilminster and Boisjoly, Mason finally turned to Bob Lund and said, "Take off your engineering hat and put on your management hat." Joe Kilminster wrote out the new recommendation and went back on line with the teleconference.

> The new recommendation stated that the cold was still a safety concern, but their people had found that the original data was indeed inconclusive and their "engineering assessment" was that launch was recommended, even though the engineers had no part in writing the new recommendation and refused to sign it.

-- https://onlineethics.virginia.edu/cases/engineering-ethics-c...

If you want to take the "system" view here, as is often the case, it is the organizational power structure and incentives therein that comprise the dangerous system. You had engineering experts easily predicting the disaster, but they had no decision making power. That was the problem. But if you set up an organization like that, where the egos of "get it done" managers are allowed to gamble with other people's lives to win their own accolades, the system is doomed from the start.