At 1758 eastern time, an amateur-built Lancair IV broke up in-flight in the vicinity of Allendale, killing all four occupants. Air traffic control data showed the flight was cruising at 17,000 feet when the pilot asked to deviate for weather. The controller offered the pilot a choice of deviating left or right, and provided headings. The pilot opted to go to the right. About 10 minutes later the flight was cleared to descend to 13,000 feet, then 11,000 feet in preparation for a landing in Buford. A witness sitting in his yard said it was thundering but had not started to rain. He heard an airplane approaching his location but could not see it due to the cloud cover. The engine sounded like it was at full power and then decreased to idle power. He then heard a sound described as an explosion. He looked in the direction of the sound and observed the cabin area come out of the clouds with the wings falling to the ground behind the airplane.