The US Postal Service-UPS rivalry vanished yesterday in the face of a common enemy: an attacking and possibly rabid pit bull. Officials say that when a UPS driver in Chicago was attacked by the dog, a passing postal worker pulled it off him and held it down for more than 15 minutes until help arrived, the Chicago Tribune reports. The UPS employee was hospitalized with injuries to his ear, head, forearm, hands, and ankle. Witnesses tell CBS 2 the postal worker probably saved the other man's life. The dog is being held for rabies observation. A Postal Service spokesman tells the Tribune that the postal worker suffered only minor injuries, and the rivals "do look out for each other." (A letter carrier in Alabama saved a man who had been trapped for 10 days.)