On January 10, 2015, about 1110 central standard time, a Cessna 152, N89921, operated by Wallace State Community College (WSCC), was substantially damaged when it impacted trees shortly after engine start, at the Cullman Regional Airport (CMD), Cullman, Alabama. The student pilot sustained minor injuries. Visual meteorological conditions prevailed and no flight plan had been filed for the instructional flight conducted under the provisions of 14 Code of Federal Regulations Part 91.According to a Federal Aviation Administration (FAA) inspector, the airplane was parked on the ramp as the student pilot prepared to conduct a local solo flight. The student pilot reported that the airplane was not equipped with a parking brake. He primed the engine four times and opened the throttle 1/4 to 1/2 inch for starting. Upon starting the engine, the airplane began to roll; however, the brakes were not effective and the throttle control would not move. The airplane continued to roll and the student pilot was able to turn enough to avoid hitting a hangar. The airplane rolled approximately 344 feet from where it was parked, struck trees and sustained substantial damage to the forward portion of the fuselage, left wing, and engine firewall. Postaccident examination of the airplane by FAA inspectors was performed on January 15, 2015. The examination included a functional check of the brakes, and did not reveal any preaccident malfunctions or failures that would have precluded normal operation. Both the throttle and mixture controls were impact damaged and could not be moved; however, they remained properly connected. It was noted that the airplane was equipped with a parking brake; however, it was ineffective due to a loose cable. School flight instructors reported that they did not teach students to utilize the parking brake during engine start because they did not want the students to rely on the parking brake and preferred to emphasize regular brake usage during engine starts. An FAA inspector further reported that ramp surveillance video showed the airplane quickly accelerating after the engine was started before it exited from camera view. According to maintenance records, the airplane had been operated about 6 hours since its most recent annual inspection, which was performed about 30 days prior to the accident. The airplane was last flown by the student pilot about 1 week prior to the accident without incident. The student pilot reported about 24 hours of total flight experience, which included 2 hours logged as pilot-in-command.