On September 15, 1993, at 2145 eastern daylight time, a Boeing 757-232, N627DL, operating as Delta Flight 250, encountered moderate turbulence climbing through 14,000 feet, approximately ten miles east of Atlanta, Georgia. A flight attendant stationed in the rear of the airplane was injured. The scheduled, domestic, passenger flight operated under 14 CFR Part 121 with a valid instrument clearance. Visual weather conditions prevailed at the time of the accident. The airplane was not damaged and one of the 188 persons on board the airplane was injured. The flight departed Atlanta at 2140 hours. According to the captain, air traffic control cleared the flight to 14,000 feet, and the seat belt sign was turned off as the airplane climbed through 10,000 feet. The flight attendants reported that the flight was normal as they started their normal inflight passenger service. As the flight climbed, the pilots observed a thin layer of clouds along their route of flight. They continued the climb through the layer of clouds; they also observed, on the airborne weather radar system, isolated cumulonimbus (CBs) type clouds about 5 miles northeast of the flight path. At 13,000 feet, the flight encountered what the captain described as moderate turbulence; the seat belt sign was immediately turned on (see attached flight attendant statements with NTSB Form 6120.1/2). The flight broke out of the cloud layer at 14,500 feet; the pilot deviated south of the CBs and continued the flight into Columbia, South Carolina. After the encounter with turbulence, the captain was informed of the injury sustained by the flight attendant. The flight landed without further incident. Additionally, the flight crew reported that turbulent conditions were encountered during their previous flight, into Atlanta, about two hours before Flight 240's departure.