What happened to Lennie's puppy in "Of Mice and Men"? What is his reaction?

Lennie accidentally kills his puppy, probably by squeezing him or hitting him too hard. Although Lennie is upset at the death of his puppy, he is more concerned about George's reaction. He is afraid that when George sees he killed his puppy, George will not let him tend the rabbits on the farm they have dreamed about owning. So, he tries to hide the body of the puppy only to have it discovered by Curley's wife. This leads to further disaster. Lennie's has been told to stay away from Curley's wife but, after a conversation with her, he accidentally kills her as well. This event forces George to have to make a final decision about what to do about Lennie. Curley's wife is not an animal and this escalation of Lennie's uncontrollable control over his own strength means Lennie faces execution or long prison term.