On July 27, 1999, at 1245 central daylight time, a Cessna A150M airplane, N2721J, was substantially damaged when it struck a stop sign and terrain during the takeoff initial climb from Alvin Airpark in Alvin, Texas. The flight instructor and student pilot aboard the airplane were not injured. The airplane was owned by De Aviation, Inc., of La Porte, Texas, and operated by Harvey and Rihn Aviation of La Porte. No flight plan was filed and visual meteorological conditions prevailed for the 14 Code of Federal Regulations Part 91 instructional flight. When the accident occurred, the airplane was departing Alvin Airpark en route to the La Porte Municipal Airport in La Porte, Texas. The flight instructor reported that the student was performing the takeoff with a flap setting of 10 degrees from the 1,500-foot grass runway. "About halfway down the runway," the instructor "realized it would be real close, if [they] made it." He assumed control of the airplane and held "the yoke back to do a soft field takeoff." The instructor stated that he thought he "pulled the nose up too far and dragged the tail." After becoming airborne, the airplane collided with a stop sign located off the airport property. Subsequently, the airplane impacted in a field, the nose landing gear collapsed, and the airplane came to rest nose down in a barbed wire fence. The flight instructor reported that he had accumulated a total of 827 flight hours. He further reported that he had given a total of 94 hours of flight instruction of which 45 hours were in a Cessna 150. No information was provided on the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) completed by the instructor regarding the flight experience of the student pilot. The student pilot did not respond to a letter from the NTSB investigator-in-charge requesting a written statement describing the accident. According to the FAA inspector, who examined the airplane, the left and right wing leading edges were dented, the firewall was wrinkled, and the left wing spar was damaged.