O.K., in grade two, our teacher was a mild sadist. She showed us depressing films and picture books, and apparently got some sick kick out of it. Most I've forgotten, but one I haven't been able to forget. I saw it in 2001, but it was probably from the '70s/'80s
It was a cartoon about these inner city kids. They were all African American. One of the boys was a comedian (I clearly remember one of his jokes being, "Today, I told a man that my shoes were hurting me. He told me that I had them on the wrong feet, and I said, 'These are the only feet that I have'"). The comedian boy had an older brother who was in a gang. There was apparently going to be some sort of big gang fight, and so the comedian boy went to stop it. In the end, he gets shot (possibly by his brother). It ends with all of the characters sad at the boy's funeral.
Something makes me think that it was either a FAT ALBERT cartoon, or that it was animated by the same artists.