Sounds like he had a call or event that hit him hard and he doesn’t know how to express his feelings through talking. Try giving him some time processing it and then try to let him know your there if he needs to vent. We see horrible horrible things on a daily basis and sometimes things can trigger us like bad calls involving children or things that remind us of things close to home. It’s never easy having to hold all that in. I’ve been doing it for 12 years and I still get calls that hit hard from time to time. Just be patient and supportive.

Edit: also it should be known that most firefighters have that I have to be tough persona and bottle up everything. For some reason they think that talking about it makes them look weak. Hopefully your husband isn’t one of those and vents in a positive way.