Are we morally obligated to help those in need if we are able to?

For some reason what comes to mind for me here is a news story I saw a few years ago. It was a video some younger guys took on their cell phone. They were showing how some man had gone into the body of water there & couldn’t swim. He was visibly struggling to get air. They were hooting, laughing, shouting things to him about being stupid. They didn’t call 911. The man drowned, he died. They watched a man struggle & die. It still makes me feel sick to my stomach today thinking how anyone could find the sight of a person frantic on the water, choking, and waving as a humorous thing & want to save the memory on video.