I checked for my city and there are a couple fire fighters with salaries of $45k-$75k a year but made $140k-$180k in just overtime and overall total comp of $220+. How does that even happen?
The usual scheme is that you are not punished for not showing up to work, but are paid overtime for taking someone else's shift. As a result, swapping shifts with someone results in a 50% pay increase for both of you. Together with other scams, the result may be even greater.