Is it a problem if a wheel falls off?

I drove it home saturday night with that problem. Drove it to work on sunday morning. I called my dad and asked him to pick me up from work since i didnt think it was safe to drive my car. He told to drive home infront of him. I drove about ten feet and he starts vigorously honking. So I pulled over and got out of the car. He says to me, "Alan, your wheel is about to fall off!" It turned out 2 of the lug nuts on my front right wheel had fallen off, and the other two were loose enough I could spin them by hand, both about halfway off.

I jacked up the car and tighted the 2 remaining nuts, and took one from a rear wheel, so 2 wheels have 3 lugnuts. I'll get to a dealership today to get 2 more. Im just not sure how all 4 lug nuts became that loose on one wheel. All the other wheels were fine. As I said in my first post, that wheel isn't balanced, so that could have caused them to become loose. Either that or someone whats me dead.

Thanks for your replies.