On July 14, 2017, about 1930 central daylight time, a Balloon Works, Firefly 8B-15, N3282P, ascended unintentionally after landing near Murfreesboro, Tennessee. The commercial pilot was not injured and one passenger was seriously injured. The commercial sightseeing flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight.According to the pilot, after a successful flight, all three passengers exited the gondola and were assisting the pilot in securing the balloon. As they were holding on to the maneuvering handles the balloon began to ascend. The pilot directed everyone to "let go" but one of the passengers continued to hold on to the maneuvering handles. As the gondola ascended the passenger was carried about 30 ft into the air, before letting go and falling to the ground. The pilot regained control of the balloon and landed.