Wicker Park resident David heard a cat banging around in the alley and discovered it had a metal can stuck on its head.  He tried to pull it off, but the cat fought him away with claws out, leaving David bloodier for his effort.  The cat could breathe, despite the can.  David borrowed a cage and scooped up the stray.  They’re on the way to the vet – looks like a happy ending for all.