Depends on the country. In the US, FDIC insurance requirements mean that depositors will be reimbursed up to $250,000 if a bank collapses, so there's very little risk. If you need more than $250,000 in cash then you should probably have multiple accounts at different banks or park the money in some other highly liquid low-risk assets that are, as much as possible, uncorrelated.
Depends on the country. In the US, FDIC insurance requirements mean that depositors will be reimbursed up to $250,000 if a bank collapses, so there's very little risk. If you need more than $250,000 in cash then you should probably have multiple accounts at different banks or park the money in some other highly liquid low-risk assets that are, as much as possible, uncorrelated.