You need to invest in your people to know when something is wrong. Firefighters are reluctant to ask for help, so you need to spot trouble and get the help members may need.

When you promote to a leadership position you are always on duty for your people. You have to answer the phone when someone reaches out to you. You may be their last call when their whole world is falling apart around them. 

As a leader you are always on, you accept that role when you are in that position. Make sure you know the resources available in your department to get the help your people need.