The investigation, conducted by Citygate Associates, examined evacuation decisions, incident communications and fire behavior during critical hours of the fire.
Investigators concluded that the fire department acted appropriately under what were described as unprecedented weather conditions. The report also found there was no evidence of bias in evacuation decisions.
"It's another slap in the face," Zaire Calvin said about the report's findings.
Calvin's sister, Evelyn, died in the Eaton Fire.
"We're in pain still, and we're still fighting for survival," Calvin said.
Evelyn is one of 18 people who died west of Lake Avenue where evacuation orders went out at 3:25 a.m. on January 8, 2025.
Only one person died east of Lake Avenue, where orders to leave were issued at 7:26 p.m. on January 7, 2025 - the night the fire erupted.
"There was no failure by Incident Command to request Evacuation Orders west of Lake Avenue sooner, nor would they have reasonably done so under the circumstances," the report said.
The report says with powerful winds grounding aircraft, Incident Command made up of fire and sheriff's department staff lost a crucial fire intelligence tool.
"Incident Command was forced to fight a fire while blind to its movements, in the dark, during extreme weather, and had no choice but to protect lives and deploy apparatus and law enforcement as neighborhoods were sequentially impacted," according to the report.
"If the winds were so high they couldn't get stuff in the air, that should have made them more alert about what's going on, on the ground," Dennis Chapman told Eyewitness News.
Chapman lost his best friend, Ed Cridland, in the fire.
"I don't think they can come out with a report a year and a quarter later and say, 'You know, I think we did it right,'" Chapman said.
"The Altadena community deserves transparency, which is why I initiated this independent investigation," said Fire Chief Anthony Marrone. "While the report provides an honest account of our operations, we recognize that no investigation can truly capture the horror and tragedy residents endured. My focus is to ensure that the lessons learned from the Eaton and Palisades Fires are turned into lasting changes that will better protect our residents and neighborhoods into the future."
Marrone declined an interview request from Eyewitness News.
Nineteen people were killed during the fire. The county fire department said it accepts the report's recommendations and has since integrated new technologies.
Since the Eaton Fire, L.A. County has a new policy that whenever there are evacuation orders, surrounding areas will automatically be sent evacuation warnings.
If that would have been the case during the Eaton Fire, western Altadena would have been warned hours earlier.
See a full copy of the report below: