Two men died after being pulled from the wreckage of a small airplane that crashed Monday morning into Culver Reservoir, near Berthoud, in Larimer County.

Deb Graves, of the Berthoud Fire Protection District, says the crash was reported at about 7:45 a.m. She said divers rescued the pair — or “extricated” them — from the plane.

Authorities say the men were removed from the plane about 8 a.m. and taken to a hospital by ambulance where they died. The Larimer County Sheriff’s Office says they were in the frigid water for about 50 minutes.

Their names have not been released.

Federal Aviation Administration spokesman Allen Kenitzer said he didn’t know where the plane — a Cessna 172 — took off from or was heading.

Kenitzer said the crash happened under “unknown circumstances” and that local authorities report only two people were aboard.

“This is all of the information we have at this time,” Kenitzer said.

The FAA and National Transportation Safety Board will investigate.

Small plane crashes into Culver Reservoir in Larimer County https://t.co/j2BD8AxLus pic.twitter.com/Vlx7wmC6Az — FOX31 Denver KDVR (@KDVR) February 27, 2017

Television news helicopter images from the scene showed what appeared to be divers inspecting the small aircraft’s partially submerged wreckage, which was near the reservoir’s shore.

Further information on the situation was not immediately released.