TIFU by congratulating someone for their dead wife.

So as an introduction I work at a health insurance and mostly man the counter in order to greet costumers or handle smaller errands.

And last week a man came in so I proceeded doing my job as usual. "Good morning, how can I help you?". I was in my receptionist persona so I'm all happy and chipper. The man immediately states his case by starting with: "Last week my son was born..." as per experience I use the small pause inbetween sentences in order to congratulate. I think that was the moment I realized something wasn't right. My suspicions were confirmed when he went on: "and my wife died a day later." Silence ensues and my stomach was churning, my chipper mood destroyed in a single move.

I know that I'm not particularly at fault for this but man what a tone setter. It's not like I haven't fucked up before. But telling a woman in a wheelchair to take a seat in the waiting area is rather amusing in comparison.

TL;DR: Because of a misleading introduction to the problem I congratulated someone who had just lost their wife.