Authorities on Saturday identified three soldiers who died when a a National Guard helicopter crashed in Minnesota.

They were named as Chief Warrant Officer 2 James A. Rogers Jr., 28; Chief Warrant Officer 2 Charles P. Nord, 30; and Sgt. Kort M. Plantenberg, 28, the Minnesota National Guard said.

The three were assigned to a general support aviation battalion in St. Cloud, Minnesota, the national guard said in a statement, and their unit had returned in May from a nine-month medical evacuation deployment to the Middle East.

The soldiers were the only people aboard the UH-60 Black Hawk when it crashed Thursday. its last known location was about 10 miles southwest of a St. Cloud airport at about 1:55 p.m., according to guard officials and NBC News affiliate KARE.

"Shortly after takeoff, the pilots initiated a mayday call," said Major Gen. Jon A. Jensen of the Minnesota National Guard in a news conference Saturday.

The crash site of the Minnesota National Guard Blackhawk helicopter that killed three service members Thursday. Brian Peterson / Star Tribune via Getty Images

The crew was on a routine maintenance flight, the type of which was "conducted almost daily," when the Black Hawk went down, he said.

Jensen said the Minnesota National Guard's UH-60s were grounded as Army investigators, with the assistance of the state guard, tried to determine what caused the crash.

"We expect our UH-60s will begin flying again shortly," he said.

He also addressed the families of the fallen: "You are not alone in your grief."