I once received a word-of-mouth warning that a particular credit-union was very shaky and to get my money out. I did, and passed on the warning to my girlfriend of the time.

She believed the local manager who said her money was safe. A month or two later, that credit-union went under, taking my girlfriend's money with it. About 40 grand. About five years later, she was given back the money by the government-of-the-day, but principal only with no interest and depreciated due to inflation during that time. She probably lost the equivalent of 10-15% of her money.