In information obtained by the National Transportation Safety Board investigator, the 31-hour student pilot reported the he had been practicing touch-and-go takeoffs and landings. Prior to takeoff, he performed a run-up in which he leaned the mixture. The student pilot had completed one touch-and-go and was in the airport traffic pattern when the loss of power occurred. He was turning from downwind to base, applied carburetor heat, extended the flaps 10 degrees, and pulled the throttle back. He noted that the airplane was descending excessively. He increased the throttle but the engine did not respond. The student pilot moved the throttle control back and forth but the engine revolutions per minute (rpm) did not increase. He could not recall what the engine rpm was indicating. He then declared an emergency and selected an emergency landing spot on a street. The left wing spar was bent when the wing impacted a street sign during the landing roll. The propeller continued to windmill until the airplane rolled to a stop. Following the accident, the Federal Aviation Administration accident coordinator test ran the Textron Lycoming O-320-E2D engine using the airplane's fuel system and onboard fuel. The engine powered normally. Throttle bursts were applied and no delay or loss in power was observed.