When I was 10 I went to my friends house up the street to go hang out. When I got to his front door I saw what looked like a bird's nest situated in the door's knocker thing. I reached inside it to see if i could feel anything when I realised I accidentally smashed one of the eggs in there. I killed a baby bird before it was born. :(
I was so sad I ran home without saying hi to my friend and cried for the rest of the day. I am still sad about it. :'(