NTSB investigators are still on scene at the Columbia (S.C.) Metropolitan Airport, sorting through the wreckage of a chartered Learjet 60SE (N999LJ) that crashed just before midnight Friday after the twinjet overran Runway 11 while on takeoff for a flight to Van Nuys (Calif.) Airport. The Learjet–owned by Inter Travel and Services and operated by Global Exec Aviation of Long Beach, Calif.–came to rest on an upslope about 1,200 feet from the end of the runway after using up the 1,000-foot safety overrun and going through a perimeter fence, down a hill and across a road. Two crewmembers and two passengers were killed in the accident. Two remaining passengers survived but suffered severe burns in the post-crash fire; both are expected to make a “full recovery.” An NTSB spokesman told AIN that “evidence points to a tire blowout” at around the time the Learjet copilot made a callout at 80 knots, according to data from the recovered cockpit voice recorder. A tire debris trail was also found at approximately 2,800 feet down the 8,602-foot runway. However, the NTSB is still unsure which tire or tires possibly blew out, as all of the jet’s tires were found deflated at the crash scene. Investigators haven’t yet said if they found any skid marks or scrapes on the runway from the Learjet, but they did indicate that its thrust reversers were found in the stowed position at the crash site.