Police said the group was in a car in at the Lucien Blackwell Community Center parking lot around 6:50 p.m. Thursday on the 700 block of North Markoe Street when shots were fired.
One bullet pierced the front windshield and landed in a headrest.
Police said one of the teens was sitting in that seat and was able to duck to avoid being hit.
Two of the teens were struck by the gunfire. An 18-year-old was shot in left leg and a 17-year-old suffered a graze wound to the head.
The grandfather sped away and stopped at 47th and Brown streets.
The injured teenagers were taken to the hospital and are listed in stable condition.
No other injuries were reported.
No arrests have been made.