On Good Friday when Our Lord was dying on the cross, there is an old story that a robin came to the cross and tried to pull out the nails from Our Lord's hands and feet. When Our Lord was dead and brought down from the cross, there was one thorn left in his head which no one was able to pull out. The robin perced on his head, and pulled out the thorn. It is said that a drop of the sacred blood fell on the robin's breast. So that is how the robin is supposed to have got the red breast. Now when a robin is killed by anyone, people think it is a terrible thing.