Is there a way to handle the event of a Service Fabric Node going down (NodeStatus change) in C#. Possibly an event I can listen for?
Assuming that you're running in Azure, you can use Azure Monitor Alerts to call a webhook, or a logic app to accomplish this.
For example:
In the Monitor - Alerts (classic) pane, select +Add activity log alert. On the Add activity log alert page, select or enter the requested information. In Criteria, make sure that you set the following values: Event category: Select Service Health. Services: Select Virtual Machine Scale Sets and Virtual Machines. Type: Select Planned maintenance.