since 2015, nearly three out of four firefighters added to the iaff fallen firefighter memorial haved from so-called occupational cancer. even more have been diagnosed. >> i was kind of hit like a mack truck. >> reporter: mark, a fire captain for the city of gilroy, california, found out he had stage 1 cancer after an accident caused a tumor on his kidney to burst. >> when i was laid out in that hospital bed for eight days, that was belittling to me because i thought of myself as pretty tough guy. but laying there helped us trying to figure out what was going on. that was a whole 'nother game. >> reporter: retired san jose, california, investigator battled multiple cancers. >> i had breast cancer in both breasts. a double mastectomy, the fourth year, the bladder cancer reoccurred. for four years i battled, and i just couldn't stay on the job. >> reporter: all three of you are cancer free as we speak? >> no. >> reporter: retired san jose captain dan has upped gone radiation and hormone therapy. >> it depends how aggressive we take care of it, how aggressive the cancer itself gets. >>