The FAA report said those killed in the crash included the pilot and three passengers. The report said the plane was a Cessna T337G registered to a Broomfield-based aviation company. State records show that company is owned by a Colorado law firm.
The crash happened around 9:41 a.m. Sunday in the 10000 block of Lefthand Canyon Drive, according to the Boulder County Sheriff’s Office.
The sheriff’s office on Sunday was only able to confirm one person was dead because of the fire that followed the crash but said they would continue their work on Monday.
“At this time, Boulder County Sheriff’s Office investigators cannot determine the number of fatalities or further information due to unsafe conditions on the scene,” the sheriff’s office said in a news release Sunday evening.
For about an hour, people living in Gold Hill and Ward were told to prepare for evacuations before the sheriff’s office gave the all-clear. Firefighters on the ground were able to get the fire mostly under control at half an acre, with support from a helicopter.
The preliminary report from the FAA Monday says the plane crashed “under unknown circumstances.”
The FAA and National Transportation Safety Board are investigating the cause of the crash.
The Boulder County Sheriff’s Office and coroner’s office both said Monday afternoon they had also confirmed four people were aboard the plane and died in the crash.
As of Thursday, the coroner's office said positive notifications for the four people were still pending further investigation. The examinations of all four are complete, but their causes and manners of death were also pending further investigation.
On Friday, WBRZ identified the three victims who were not the pilot as Ian Kirby, 17, Amanda Kirby, 13, and their mother Sandra Kirby.
A NTSB spokesperson told Denver7 Thursday that the NTSB investigators arrived Monday. Their initial report showed the plane was being operated by Bluebird Aviation as a local air tour flight. It both department and was set to return to Rocky Mountain Metropolitan Airport in Broomfield.
Flight tracking data showed the plane entered a descending left turn that continued until the plane crashed, according to NTSB spokesperson Peter Knudson.
Knudson said the fire that followed the crash consumed a lot of evidence, but he was confident the NTSB would be able to determine the cause of the crash.
"We have done many, many investigations where there were significant post-crash fires and have been able to determine probable cause," Knudson said.
The preliminary investigation will focus on documenting perishable evidence at the scene, the angle of impact, and tracking down and speaking with witnesses. A preliminary report for the crash will likely be released in the next two or three weeks, Knudson said.