After any insurance limits are reached, a governmental body is a 'self-insurer' which means the taxpayers are the ultimate payers for any stupidity or negligence by a governmental employee.

The "self-insured retentions" referenced above are usually sums of money kept in reserve accounts to cover employee stupidity or negligence that exceeds the policy limits they have bought on the insurance market.   If they run out of that money, then we taxpayers get to foot the bill for the employee stupidity or negligence.