A Minnesota Army National Guard helicopter crashed Thursday afternoon in Stearns County, southwest of St. Cloud, Minn., killing all three soldiers aboard.

The UH-60 Black Hawk helicopter took off from St. Cloud around 2 p.m. for what the Guard described as a “maintenance test flight” and called mayday about nine minutes after takeoff.

Gov. Tim Walz confirmed the crash and the deaths at an evening briefing with reporters.

“They paid the ultimate price in service to Minnesota and to the United States of America,” said Walz, a retired member of the Minnesota Army National Guard. “Words will never ease the pain of this tragic loss.”

The names of the dead will be released following notification of family members, he said, adding that the “coming days will be dark and difficult.”

Stearns County authorities said it took several hours to find the craft following the mayday signal. Emergency responders, including an aviation rescue team from St. Paul, rushed to the scene after it was discovered by a State Patrol helicopter in trees by a field about 16 miles from St. Cloud, near Kimball, Minn.

Walz said the information about the cause of the crash is “preliminary” and that a comprehensive investigation would take place. Army investigators from Alabama were headed to the scene, he added.

Brig. Gen. Sandy Best speaks to reporters during the press conference. Paul Middlestaedt for MPR News

"Our Minnesota National Guard family is devastated by the deaths of these soldiers, and our priority right now is ensuring that our families are taken care of,” said Brig. Gen. Sandy Best, deputy adjutant general of the Minnesota National Guard.