Databases that failed

I’m looking for examples of database systems that failed. I note the the FBI has provided a new example: “The bureau is so convinced that the software, known as Virtual Case File, will not work as planned that it has taken steps to begin soliciting proposals from outside contractors for new software, officials said. So far the
overhaul has cost $581 million”.

Does anyone have other examples of expensive failures? The Canadian Gun Registry? The two Washington State Ferry System databases? Others?