Two people were found dead in the wreckage of a single-engine plane that crashed Sunday evening in Boulder County.

The wreckage, from a plane identified by the Federal Aviation Administration as a Diamond DA40, crashed around 9:30 p.m. Sunday about four miles west of Mountain View Fire Rescue Station 9, 4390 Eldorado Springs Drive.

Boulder County Sheriff’s officials learned about the crash at 9:42 p.m. from an alert from the U.S. Air Force Rescue Coordination Center, Boulder County Sheriff’s Office spokesperson Vinnie Montez said during a Monday morning news conference. Crews found the wreckage about 10:15 a.m. Monday, according to a Sheriff’s Office post on X.

When crews got to the crash site about noon, they did not find any survivors, the post says. The Boulder County Coroner will identify the victims and specify the cause and manner of their deaths once their families have been notified. One family member related to one of the victims has been speaking with officials, Montez said.

He said no fire was reported at the crash site.

Montez said the plane departed from Longmont’s Vance Brand Airport on Sunday evening, but he couldn’t say where it was headed because private planes don’t have to file flight plans. He also did not know what time the plane took off Sunday evening.

Clear skies and calm winds helped with the search effort, which began Sunday night and continued Monday morning after an overnight break, Montez said.

Responders had to be meticulous in their search because tree cover is dense enough in some areas that the ground isn’t visible from search-and-rescue aircraft, Montez said.

Civil Air Patrol and MedEvac air crews first identified the wreckage, Montez said.

“The area is rugged, the terrain is definitely difficult up in that area, and it took until approximately noon for responders from Rocky Mountain Rescue (Group), Boulder Emergency Squad, Boulder Mountain Parks and Open Space and other crews to get up to the scene,” said Montez, who added that a team from the National Transportation Safety Board will arrive on the scene on Tuesday and lead the investigation.

Once the wreckage was identified, Montez said crews approached the site on foot.

“There’s no immediate trails up to it or anything like that from what I could see. The terrain, the elevation, the incline, to me, it looks like it’s pretty difficult,” said Montez, who said he reviewed images from the scene.

He later said that the search and rescue efforts took time because “you want to do it safely. It doesn’t help if we get somebody injured.”

The Federal Aviation Administration and the National Transportation Safety Board will investigate the circumstances of the crash starting Tuesday, according to the Sheriff’s Office post. The NTSB will have a team on scene on Tuesday, Montez said.

A flight restriction is in place around the scene until around 10:15 a.m. Tuesday, Montez said.

This is a developing story and may be updated.