The pilot of the helicopter that crashed in thick fog, killing NBA legend Kobe Bryant and all eight others on board, reported that he was climbing when he was actually descending, federal investigators have said.
Pilot Ara Zobayan likely became disoriented in the fog before the crash in foothills near Los Angeles on January 26, investigators said in documents released on Wednesday.
The National Transportation Safety Board (NTSB) report said Mr Zobayan told air traffic controllers that his helicopter was climbing, when in fact it was descending shortly before slamming into a hillside outside the community of Calabasas.
The crash killed LA Lakers icon Bryant, his daughter Gianna, Mr Zobayan and the six others on board, who were travelling to a basketball tournament.
The NTSB said that pilots can become confused over an aircraft's attitude and acceleration when they cannot see the sky or landscape around them, causing "spacial disorientation."
The report said: "Without outside references or attention to the helicopter's attitude display, the actual pitch and bank angles have the potential to be misperceived."
The findings came in a 'public docket' released by the NTSB as it investigates the crash. The agency has not yet released its final report.
According to AP, Mr Zobayan radioed to air traffic controllers that he was climbing to 4,000 feet (1,220 meters) to get above clouds when, in fact, the helicopter was plunging toward a hillside.
As well as killing Bryant, 41, and his daughter Gianna, 13, the crash also claimed the lives of John Altobelli, 56, his wife Keri, 46, and their daughter Alyssa, 14; Payton Chester, 13, and her mother Sarah Chester, 46; and Christina Mauser, 38.
Autopsy reports released last month gave the cause of death for all nine victims as "blunt trauma", while the manner of death was certified as "accident".
The autopsy into the death of 50-year-old Mr Zobayan revealed there were no alcohol or drugs in his system. He had lengthy experience in the air. He had 8,200 hours of total flight time and had completed the same route the day before, albeit in clear conditions.
Jennifer Homendy, a board member on the National Transportation Safety Board, described the accident as a “high energy impact crash” after the S-76B helicopter suffered a descent rate of 2,000 feet per minute.
Bryant, regarded as one of the greatest basketball players of all time, represented the Los Angeles Lakers for all of his 20-year career and also won two Olympic gold medals before retiring in 2016.
He was survived by his wife Vanessa and their other three daughters Bianka, Capri and Natalia.
He retired in 2016 as the third-leading scorer in NBA history, although he has since been passed by another Lakers star, LeBron James.
The tragic death of Bryant and his daughter Gianna, known affectionately as 'GiGi', prompted tributes from throughout the sporting world and beyond.
A public memorial to Bryant and the others who tragically died in the crash saw more than 88,000 people apply for tickets, with a limited number available to the general public.
The rest were reserved for friends, family and members of the NBA community.
The likes of fellow basketball legends Kareem Abdul-Jabbar, LeBron James, Steph Curry and 'Magic' Johnson were all in attendance.