On October 14, 2016, about 1735 eastern daylight time, a Cessna 208, N208KM, was substantially damaged during a skydiving event over Marion County Airport (X35), Dunnellon, Florida. One of the 10 skydivers on board was fatally injured, and the commercial pilot and the other 9 skydivers were not injured. The airplane was registered to a private individual and operated by the National Parachute Test Center, Inc., (NPTC) under the provisions of Title 14 Code of Federal Regulations Part 91 as a commercial skydiving flight. Visual meteorological conditions prevailed, and no flight plan was filed for the local flight, which departed X35 about 1700.According to a report prepared by NPTC, in addition to the pilot, there were 8 jumpers, a jumpmaster, and a training advisor assigned to the flight. Before boarding the airplane, the training advisor, who was a skydiving instructor familiar with the airplane, instructed the jumpmaster on the procedure used to make static line jumps from the Cessna 208. Upon boarding the airplane, the jumpmaster elected not to hook up the static line of his main parachute. When questioned by the training advisor, the jumpmaster replied, "I am not going to jump, so I do not have to." The flight departed and climbed to an altitude of 1,250 ft above ground level. According to the NPTC report, the first three skydivers exited the airplane uneventfully, and the fourth moved into position. The training advisor observed that the fourth skydiver seemed to hesitate, and the jumpmaster leaned forward toward him. As the fourth jumper exited the airplane, the training advisor noticed a flash of white and watched as the jumpmaster's reserve parachute deployed and entered the airplane's slipstream. The jumpmaster attempted to pull the parachute back into the airplane and was pulled into the door frame before being dragged out of the airplane. Observers on the ground watched as the jumpmaster descended beneath his streaming (unopened) reserve parachute to the ground. The ground observers reported that the jumpmaster made no movements, appeared to be unconscious, and did not deploy his main parachute. The pilot reported that he was able to maintain control of the airplane and land without further incident. Examination of the airplane by a Federal Aviation Administration (FAA) inspector revealed that the cargo door frame and fuselage were buckled. Inspection of the jumpmaster's main parachute by an FAA-certificated senior parachute rigger revealed that it was intact and remained in the deployment bag. Examination of the reserve parachute revealed that the injector spring was wrapped around the suspension lines. The deployment ring, connector snap, and part of the spreader bar were located midway up the suspension lines. The jump inspection booklet located on the parachute indicated that the reserve parachute was inspected 3 days before the accident. NPTC attributed the damage to the reserve parachute to impact with the door frame as the jumpmaster was pulled from the airplane. The FAA inspector who examined the airplane reported that the jumpmaster was using a military-style parachute with the reserve parachute positioned below the chest. According to the FAA inspector, "the reason the reserve parachute deployed is unclear at this time but since the D ring [ripcord handle] is exposed on the front of the parachute speculation is that the D ring may have accidently caught or snagged on another jumper or something in the aircraft." According to NPTC, the accident resulted from the jumpmaster's "failure to guard his Reserve Ripcord Handle" and "was compounded by [his] failure to exit the aircraft immediately" when his reserve parachute deployed.