In the USA there are a few organizations which insure depositors against bank collapses. Other regulatory agencies supervise banks, audit them, regulate them. It seems that you cannot be too cautious where banks are concerned. Italian bankers used to do their businesses on benches. Nothing much changed ever since - maybe with the exception of the scenery.
Banks hide their fragility and vulnerability behinds marble walls.
Sometimes they hide worse things. A series of bank scandals is sweeping through much of the developing and third worlds - Eastern and Central Europe in the forefront. Many things - almost everything. It is mainly a crisis of trust and adverse psychology. Financial experts know that Markets work on expectations and evaluations, fears and hopes.