On January 3, 2014, at approximately 1930 pacific standard time, Southwest Airlines flight 2516, a Boeing 737-800, N8327A, experienced a tail strike during landing at McCarran International Airport (KLAS), Las Vegas, Nevada. There were no injuries to the 180 passengers and crew onboard and the airplane was substantially damaged. The flight was operating as a regularly scheduled passenger flight and originated from Orlando International Airport (KMCO), Orlando, Florida. According to the operator, the captain was the pilot flying and the first officer (FO) was the pilot monitoring. The accident flight was the first and only scheduled flight for the day for both crew members. Both pilots indicated that takeoff through the initial descent was uneventful. The aircraft was configured for a flaps 30 landing. During the ILS approach to runway 25L, the captain used the Heads-up Guidance System (HGS) in the IMC mode. During the decent below 100 feet, the FO indicated that the runway environment was dark and sensed the runway was "coming close fast". He noted a slightly increased descent rate and before he could make a callout, the captain had begun to take corrective action. During the descent, the captain stated he was hand flying the airplane (autopilot and autothrottles were off) and used the localizer, glideslope and flare cues from the HGS. At approximately 30 feet, he transitioned from the HGS to the runway environment, noting it appeared "pitch black." He then noticed the runway edge lights and what appeared to be an increased sink rate. Both pilots indicated the airplane touched down firm, then bounced, and the second touch down was harder than the first. Neither were aware that they had struck the tail. The captain did not recall seeing a tail strike warning indication from the HGS. Post flight inspection revealed that the tail strike indicator was compressed and deep scrapes and wear damage to the lower aft fuselage skin. Further investigation revealed multiple fractured frames and buckled stringers, shear ties and straps.