On May 29, 2002,at 1308 eastern daylight time, a Boeing 757-200, N626DL, registered to Delta Airlines Inc, operating as Flight 721, encountered turbulence on descent to land at Hartsfield International Airport, Atlanta, Georgia. The domestic passenger flight was operated under the provisions of Title 14 CFR Part 121 with an instrument flight plan filed. Visual weather conditions prevailed at the time of the accident. The airplane was not damaged. One flight attendant received serious injuries. The airline transport rated captain, the airline transport rated first officer and the 88 passengers were not injured. The passenger flight departed Chicago O'Hare International Airport, Chicago, Illinois, at 1040 central daylight time. According to the captain, flight 721 was cleared to descend out of flight level 240, and at this time the " fasten seat belt sign" was illuminated. The weather condition for the arrival consisted of broken clouds at approximately 10,000 feet. There were no reports of enroute or destination turbulence. Flight 721 was deviating around cumulonimbus clouds at approximately 11,500 feet over Rome, Georgia when the airplane entered an area of turbulence. The injured flight attendant was completing pre-landing checks for the cabin when the airplane encountered turbulence during the descent into Atlanta Hartsfield International Airport. The flight attendant was injured when she was jolted around the rear of the passenger cabin. According to the flight attendants, prior to the initial approach into Hartsfield International Airport, they were preparing both cabins and galleys for landing. Without any advanced warning they unexpectedly encountered severe turbulence that lasted for a brief period of time. This severe turbulence was then followed by moderate turbulence. After the moderate turbulence one of the aft flight attendants were injured and needed medical attention. The flight attendants notified the cockpit and requested paramedics after landing. The flight attendants received a return call confirming that paramedics were alerted and would meet the flight after landing. According to the lead flight attendant, the seat belt sign was turned on, and the airplane was on its initial descent into Atlanta Hartsfield International Airport. A passenger rang the call light for assistance with an ear pain. As the attendant went back towards the galley to get the passenger first aid, the airplane was suddenly jolted by turbulence. The flight attendant stated, she " flew into the air and was jarred around". When the turbulence stopped, the flight attendant hit the floor slid back towards the galley. The flight attendant called for assistance from another attendant, and contacted the captain to inform him of the situation. After the airplane landed paramedics came on board to administer first aid to the left foot of the injured flight attendant.