SAN FRANCISCO (CBS SF) — Officials with an aircraft company that transports medical patients by plane have released the names of three people who died in a crash of an Oakland-bound flight last week.

Pilot Larry Mills, Flight Nurse Deborah Kroon, Flight Paramedic Michelle Tarwater and a patient were bound for Oakland International Airport from Crescent City early Friday morning when their Piper Cheyenne plane went down in Humboldt County, Cal-Ore Life Flight officials said.

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“This is one of the saddest moments in our history,” president of Cal-Ore’s parent company Reach Air Medical Services said in a statement.

The identity of the patient being transported has not been release. The patient was in transit to undergo treatment at San Francisco’s California Pacific Medical Center.

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Investigators from the National Transportation Safety Board arrived at the crash scene on Sunday.

A Humboldt County Sheriff’s Office search and rescue team found the crash at about 10 a.m. on the property of a private timber company in an area north of Arcata. The plane left Crescent City Airport at 12:29 a.m.

The plane went missing near Arcata after Mills reported smoke in the cockpit at about 1 a.m., according to the Federal Aviation Administration.

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Mills notified air traffic controllers that he was going to return to Crescent City and Cal-Ore officials said they lost contact with Mills at 1:05 a.m.