Yes it is!!! I dont know how old you are or why you feel this way.. But in my opinion..someday you may have children .. If you dont already.. And they (the children) will suffer your wrong doings... God & Karma work hand in hand... Be careful of your thoughts.. Words and actions.. Everything has consequences!
It's normaal but it's not good. But I think most ppl at some point wish death upon somebody else because of whatever reason. That feeling goes away tho unless your holding a grudge against that person. It's not good for you or your health.
If you are wishing so just because you're angry or something, yes it is. You may not like that person but there's someone who would want that person alive. Having that said, I myself wished for someone to die because I saw her suffering so much in the hospital. She finally died there and although I was very young at that time, still today I wish I never said those words.
I just wish that they get something painful where parts of them fall off but it's NOT fatal so they have to live in pain and/ or without the part that fell off, especially if that was their favorite part or what they bragged about/ rubbed in peoples faces ;-)