Here are two public engineering failures in today's news: more bad news about Fukushima and the so-called glitches in the Obamacare roll-out.
I think we have a pretty good idea of the process that went wrong at Fukushima and here are some educated guesses about the healthcare rollout. The two failures have some similarities, despite being of vastly different effects and engineering disciplines. In both cases you can see the results of engineering being done by people who are doing it for the first time (20 years to build a nuke), with no full-scale test. Likely many decisions were made in both cases by upper managers who are insulated from the hard facts of the process, but highly susceptible to financial and political pressure. In both cases the owner is an organization whose main business is something else entirely ( electric grid, government) but who can't take the risk of trusting experts.
Civil engineering is peculiarly plagued by the testing problem, where they have to use computer models to predict behavior at the macro scale, and nuclear plants are as complex and dangerous as anything they build. The healthcare website could have been tested, and probably was at some scale. My guess is the healthcare sites have a combination of buggy software they wrote in-house, and a poor plan to scale the size if more-than-expected hits appeared, and dependencies on exiting data sources that don't scale. Rigid dependencies, like a central database server that doesn't scale ( just a guess), can create single points of failure that stop the user interface cold. Testing with large numbers of non-expert users, and with with assumptions=failure ( instead of assuming success ) - these are engineering 101, but this forest is routinely lost among the trees of immediate cost, deadlines, and security concerns. In the end the big picture is late, embarrasing, and expensive, but we just aren't that kind of visionary monkey by nature - we have to be trained to it. Of course if they depended on Oracle or Microsoft, well then c'est tout.