I replied to a tweet sent to me, but now can't find the original

Someone sent me a tweet to which I replied. Now I can see my reply, but not the original (I didn't save it) and can't find the sender's @XXXXX on twitter.
Any ideas what happened or how I can see the original tweet?

 

The sender has probably been blocked by Twitter that's why you can't see him/her and his/her tweets.

 

Thanks! What would cause someone to be banned by Twitter?

 

Any number of reasons really, the biggest one is probably spam.

 

Spamming. If you mention too many random people(who are not following you) a day, you'll be blocked(not banned) by Twitter.

 

When I started Twitter I used to mention Celebrities a lot, which prompted twitter to block my account. I then contacted them and asked them to unblock my account and assured them I won't do that again and they unblocked me

 

Yes, the original tweet could have been considered spam.