American Airlines flight AA923, a Boeing 757-223, was damaged when the tail section struck the runway during landing at La Paz. Instrument meteorological conditions prevailed at the time and an instrument flight rules flight plan was filed. The aircraft received substantial damage. There were no injuries. The flight originated from Miami, Florida, on September 20, 1998, about 23:53 eastern daylight time. The captain reported to the operator that he was flying the aircraft at the time of the accident. During landing flare he allowed the nose of the aircraft to rise too much in an attempt to prevent the nose landing gear from slamming down. After arriving at the gate he was informed by a flight attendant that they heard a scrapping nose in the tail area of the aircraft during landing. He inspected the aircraft and found a 6 to 8 foot scrape mark on the tail section of the aircraft. Examination of the aircraft by company maintenance personnel showed the aft pressure bulkhead had a 1-inch depth buckle and that there was a small crack in a frame aft of the aft pressure bulkhead. There was abrasion damage from station 1681.8 to 1720. The lower cap of the aft pressure bulkhead was exposed at station 1720.