On August 8, 1999, about 0915 eastern daylight time, a Cessna 172R, N9514Q, registered to J & S Aircraft Services, Inc., operating as a Title 14 CFR Part 91 instructional flight, crashed on takeoff during a touch-and-go landing at Savannah International Airport, Savannah, Georgia. Visual meteorological conditions prevailed and no flight plan was filed. The airplane received substantial damage and the student pilot, the sole occupant, was not injured. The flight originated from the same airport about 0830. According to the student pilot, he was performing his second touch-and-go landing, and touched down left of runway 27 centerline. Following his touchdown, while adding power for the "go" he tried to steer closer to the centerline using right rudder; however, the airplane continued veering left until it departed the runway and collided with a runway sign. The airplane continued across the infield, crossed an intersecting runway, (runway 18/36), ground looped, recrossed the intersecting runway, and came to rest on the east side of runway 18/36. The student pilot did not indicate that he thought the accident was caused by any mechanical failure of the airplane. Subsequent examination of the airplane by FAA personnel revealed the left main wheel assembly had separated due to collision with the runway sign. Maintenance records revealed no previous flight control or braking system malfunctions. Airport winds reported about 20 minutes before the accident were from 250 degrees at 8 knots. The pilot reported that he encountered no wind gusts or turbulence.