Video coming out of Arizona shows a shocking attack by a Wendy's employee on an elderly customer, knocking the man unconscious and leaving him fighting for his life. 

Authorities say the assault came in response to the elderly customer's complaint about the order. By the time the customer was sucker punched by employee Antoine Kendrick, 35, who was seen on grabbing his belongings and leaving the fast food restaurant while the elderly customer lay on the floor unconscious. 

Kendrick has since been booked on one count of aggravated assault. 

Source: Nypost.com