The death of a  Detroit Burger King customer has been ruled a homicide. Police say 67-year-old Paul Cannon fell and later died after being punched by a 20-year-old employee.

The incident happened Thursday evening at a Burger King restaurant on Gratiot, near St. Aubin, on Detroit’s east side.

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According to Detroit Police, Cannon was reportedly causing a disturbance Thursday afternoon and tried to hit the worker, who swung back.

Police say the punch knocked Cannon to the floor. He was rushed to a hospital where he died a short time later.

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Wayne County medical examiner’s office spokesman Dennis Niemiec said an autopsy conducted Friday determined that Cannon died from blunt force trauma to the head.

Niemiec says the man’s dentures were “not an issue” in the death. An earlier report said the punch may have caused the older man to choke on his dentures.

 The worker was in police custody Friday. His name was not immediately released.

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(Copyright 2010. WWJ Newsradio 950. All Rights Reserved. The Associated Press contributed to this report.)