All four people aboard were killed when a small plane crashed near Lefthand Canyon Drive on Sunday, according to a preliminary report from the Federal Aviation Administration (FAA).

The crash was reported about 9:40 a.m. in the 11000 block of Lefthand Canyon Drive, between Gold Hill and Ward. The plane, a twin-engine Cessna P337, crashed in a heavily wooded area on the south side of the road, according to the Boulder County Sheriff’s Office.

Monday the FAA said there were four fatalities when the plane crashed under unknown circumstances.

Read the full story from Denver Gazette news partner KUSA here.