As I was a child I saw a few minutes from a sci-fi movie on a video tape of my parents, but it was so horrifying, that I did not watch it.
The scene I can remember, that people (maybe soldiers) find a kind of bunker in a city. As far as I can remember the city looked like after a (apocalyptic?) war. In the bunker there was one man. In the next scene, somehow the man is outside of the bunker and the others are inside, and they see through the window of the bunker door the other guy dying, as something is happening outside (maybe gas? attack). I am not sure but maybe also a display showed inside the bunker that it is dangerous outside. After that they left the bunker and looked around.
I am not sure at the following (maybe I dreamt it, I do not know): after they left the bunker they checked a main cannon of a tank, and it pulverized in their hands.
I saw the scene before 1993 maybe at the end of the '80. The movie was in color, and was produced in the USA or somewhere else in the west. And I think it was not an episode of a series, but more a movie.