The most common serious injuries were multiple lower leg fractures and dislocations, spinal fractures, hip fractures, head injuries, and multiple lacerations and contusions. The NTSB investigators found severe damage on the floor of the cabin, leading many of the passengers' seats to fracture where the legs met the floor track. This fracturing permitted many of the seats to come loose during the impact and aggravated the passengers' injuries. The report posits that the passengers' legs hit the lower seat frames in front of them. At the same time, the seats collapsed and twisted downward and to the left, likely causing hip and spinal fractures. As the impact progressed, the seats, now separated, flung passengers forward into each other as well as into other wreckage, causing head injuries and lacerations. Passengers holding onto infants reported being unable to either prevent their children from being ejected from their grasp in the impact or locate their children in the darkness afterward. The NTSB held that, had the children been in Federal Aviation Administration (FAA)-approved child seats, many injuries might have been mitigated. Rescuers remarked that some infants were found smiling or seemingly unharmed. The NTSB was unable to accurately chart where individual passengers were seated because Avianca only assigned seats to a few passengers and many who were assigned reported moving after takeoff.