The National Transportation Safety Board found no evidence of an engine failure in the helicopter crash that killed Kobe Bryant, his 13-year-old daughter and seven others, according to the agency's preliminary report.
The preliminary report on the Jan. 26 crash was released Friday.
Along with Bryant and his daughter Gianna "Gigi" Bryant, the other victims were identified as college baseball coach John Altobelli, his wife Keri Altobelli and their daughter Alyssa Altobelli; girls' basketball coach Christina Mauser; Sarah Chester and her daughter Payton Chester; and pilot Ara Zobayan.
While no cause was listed, the report offered details about the aircraft's flight and rapid descent.
After the 1991 Sikorsky S-76B aircraft gained altitude over the 101 freeway near Calabasas, California, it started a left turn but then descended at 183 mph while still making the turn, according to the NTSB.
A witness in the mountain bike park, where the wreckage was found, reported hearing a normal sounding helicopter.
Yet he then saw the aircraft "emerge from the clouds" and moving in a forward but descending trajectory.
"It started to roll to the left such that he caught a glimpse of its belly. He observed it for 1 to 2 seconds, before it impacted terrain," according to the report.
The engines from the helicopter were found in a burned area and while parts were destroyed, the pieces that could be seen showed that main and tail rotors were rotating and there was "no evidence of an uncontained or catastrophic internal failure," according to the preliminary report.
There was evidence that the rotor blades hit trees before hitting the ground, according to the report.
The impact of the crash left a crater in a hilly terrain near Calabasas that was 24 feet-by-15 feet in diameter and 2 feet deep.
Weather conditions on Sunday morning caused the Los Angeles Police Department and the Los Angeles Sheriff's Department to ground its fleet of choppers. Still, NTSB member Jennifer Homendy, who's leading the investigation into the crash, said comparing that decision to the decision made by Bryant's pilot is "an apples to oranges comparison."
"We have to look at this specific crash and this specific helicopter," Homendy previously said.
The helicopter was not equipped with a flight data recorder or a cockpit voice recorder, but the NTSB report notes that it was not required to be for the flight.
The remains of all of the victims have been recovered from the crash site.
The NTSB report comes a day after a memorial service for Bryant and his daughter was announced.
A public service will be held on the morning of Feb. 24 at the Staples Center in Los Angeles.