Police say it all started just before 3:00 on Wednesday morning, at Chelten and Chew avenues in the Germantown section of the city.
That's where investigators say two men tried to rob two other men.
During the robbery, one of the suspects pulled out a gun and shot one of the victims, wounding him in the stomach.
The wounded man was rushed to the hospital, where doctors are trying to save his life.
The robbers are on the loose.