Oh, that kind of incident management. That's just routine task management.
FEMA has something called the National Incident Management System, which is used when large scale bad stuff happens.[1] Many municipal employees get training on this, so they know what to do in a crisis. Incident commanders require substantial training. There's a certification system and even wallet cards, to keep clueless officials from trying to run things. It's not that complicated, but it's been thought through by people with dozens of disasters behind them.
There's always a single incident commander. It's usually somebody like a fire chief, not a political official.