On April 21, 2003, at 1610 eastern daylight time, a Boeing 757-222, N504UA, operated by United Airlines as flight 705, encountered turbulence during cruise at flight level (FL) 290 near Lithonia, Georgia. Instrument meteorological conditions with convective activity prevailed at the time of the accident. The 14 CFR Part 121 domestic passenger flight was operating on an instrument rules flight plan. One flight attendant received minor injuries and a second flight attendant received serious injuries. The 2 flight crew, 3 remaining flight attendants, and 179 passengers reported no injuries. The flight originated from Orlando International Airport, Orlando, Florida, at 1520, en route to Chicago O'Hare International Airport (ORD), Chicago, Illinois. The flight crew reported deviating for weather. Air traffic control (ATC) cleared them to descend to flight level (FL) 290. The flight crew reported they could see the "end of the line of showers" to the north and deviated further to avoid showers. ATC then cleared them to climb to FL 310. During the climb, they experienced four to five seconds of turbulence, described as "moderate with a strong updraft for a few seconds." When they exited the top of the cloud layer, they were contacted by a flight attendant who indicated one of the flight attendants had been seriously injured. The first officer requested medical assistance and contacted dispatch to request paramedics to meet the airplane at ORD. The injured flight attended reported receiving a message from another flight attendant to return to her seat and strap in. She stated she was on her way back to her jump seat when the turbulence started. She reported she "flew into the air" and her left leg hit a counter in the galley. The flight attendant received a fracture to her left tibia and fibia. She stated that two doctors on board the airplane came to help her after the turbulence had subsided. The Federal Aviation Administration, Boeing, and UAL were parties to the investigation.