All legit banks will purchase FDIC insurance and this FDIC insurance takes care of and protects the depositor in the event the bank fails.
The FDIC will guarantee and insure bank accounts with an amount of $250,000.00 per depositor per bank and if you have anymore than $250,000.00 in one bank account the FDIC will not be able to insurance and replace more than that $250,000.00
So if you're wealthy and have more than $250,000.00 to keep in a bank account you should spread that amount through different banks in different bank accounts to be safe.