How do i go about looking up my grandpas death?

i live in the small Town of weatherford tx my grandfather hung himself in the cemetery when i was 2 i remember him even though my mom says i was to little to remember anything about him. he hung himself in the cemetery across the street where we lived with mine & my sisters jump rope that much i know but i want to try to get more information his name is mathias hernandez dies may22 1977 weatherford tx my family is so secretive the only person that told me what happened was my aunt carla & she died last year of cancer so i want to find out more how do i go about doing this? do the libraries carry information that far back?