Is it bad that i am able to rejoice in someone's death?

This has only happened once or twice. But the main incident was when I knew someone at one point who was a total piece of shit. Was not offering anything of any value to the world, only taking from it. Sadistic sociopath type. Well, eventually I find out through social media that he had died in a car crash. So many people cried "rest in piece" but I couldn't understand why. I guess he showed a different side of himself to them, but I could not fathom why anyone would be upset that someone like that had died early. I saw the world becoming an ever so slightly better place because of his death. So I rejoiced inside.

Is this something that you see as bad or immoral?