Mr. Reles , a Murder Incorporated assassin -- known at the time on the streets of Brooklyn as Kid Twist , and then , after his untimely demise , as the Canary Who Could Sing but Could Not Fly -- fell , or was pushed , out a sixth-floor window of the Half Moon Hotel on Coney Island , where he was under guard waiting to testify against one of the leaders of the killing combine , Louis -LRB- Lepke -RRB- Buchalter .