Your dad had heavy asbestos exposure if he was a boilermaker. That and smoking raised his chances of getting lung cancer substantially. Sorry for your loss.
Oh, that I know all to well. God only knows what toxins he breathed on the battle field that was a contributing factor too. He was a T/5. 5 major battles in the Pacific,during his 6 yrs in the Pacific, including Corrigidor, where he and a PFC put OUR FLAG back up on a telegraph pole under sniper fire. Bronze Star, 503rd Airborne. He also went into Japan at Nagasaki after the war has ‘officially’ ended. Some of those chems they used in WW2 are now banned.
The fact the VA never found it until to late, is the real issue. He was getting chest xrays every 3 months. He was not on OX either.
I miss my Dad, but know he is in a far better place. And I’ll see him inside the Eastern Gate 1 day.
Which is why I fuss at my grown sons for the bad habit. 1 has a 12 yr old, real fine example he sets. That and his BAD language. They did not learn it at home. Sarc/