On July 02, 2002, at 0922 central daylight time, a McDonnell Douglas MD-88 transport airplane, N911DL, operating as Delta flight 239, was substantially damaged when the left wing of the airplane collided with a parked construction truck while taxiing to Gate 29 at the Houston Hobby Airport (HOU), near Houston, Texas. There were no injuries to the 5 crewmembers and the 58 passengers. There were no reported injuries to anyone on the ground. The airplane, owned by the Wilmington Trust Company of Wilmington, Delaware, was being operated on a scheduled domestic passenger flight by Delta Airlines, of Atlanta, Georgia, under 14 Code of Federal Regulations Part 121. Visual meteorological conditions prevailed and an IFR flight plan was filed. The flight originated from Atlanta, Georgia, at 0730. After landing on runway 12R, flight 239 was cleared by ground control to "cross runway 22 and taxi to the gate." The pilot taxied on taxiway Zulu, which is parallel to taxiway Yankee. Taxiway Zulu was closed due to construction; however, the construction was not posted on the ATIS, NOTAM's, or the dispatcher’s release from the company. Ground control did not mention that Taxiway Zulu was closed. As the aircraft taxied to Gate 26, a heavy duty fork lift and a construction truck with a trailer loaded with aluminum siding were parked on the left side of taxiway Zulu. As the airplane taxied by the construction area, the left wing skipped over top of the parked forklift and collided with a load of siding material that was loaded on the trailer being towed by the parked truck. A stack of siding material loaded on the top of the trailer was pushed forward onto the rear window of the truck, with the decking material penetrating the rear window. There were no reported injuries to anyone on the ground. Examination of damaged left wing by the operator revealed that the leading edge of the left wing , about 2 feet from the wing tip, received a 3-foot puncture approximately 6 inches deep. Additionally, deep scratches, yellow paint transfers, and torn skin were found on the underside of the left wing starting from the leading edge, and continuing to the trailing edge. According to the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), the captain stated that upon landing on runway 12R at HOU, he received clearance from ground control to taxi to the gate. The captain taxied the airplane along taxiway Charlie toward the gate. As he approached the ramp area, he turned left onto taxiway Yankee. He observed construction work separated by a barricade to his left, and to his right parked aircraft. He made his transition to taxiway Zulu, and while taxing along the centerline of taxiway Zulu, felt a vibration that lasted for a brief period. There where no indications of any abnormality. Shortly thereafter, the captain taxied to gate 26 at concourse C. Ground personnel entered the jetway and informed him that moments before the aircraft arrived at the gate, the left wing of the aircraft came in contact with a ground vehicle. The FAA inspector, who traveled to the accident site, reported that the number one slat and left aileron were damaged and the left wing sustained structural damage. No fuel spilled from the left wing. The flight taxied to the gate under its own power, where passengers disembarked the airplane by normal means. Taxiway Zulu was closed by way of barricades following the mishap.