Charlotte, N.C. — Family members have identified two members of the North Carolina Air National Guard who died when their tanker aircraft crashed into a mountain late Sunday while fighting wildfires in South Dakota and Wyoming.

Relatives said Lt. Col. Paul Mikeal and Master Sgt. Robert Cannon were killed in the crash.

Two of eight C-130 Hercules planes fighting the fires were from the North Carolina Air National Guard's 145th Airlift Wing, which is based in Charlotte. The unit sent the aircraft to Peterson Air Force Base near Colorado Springs, Colo., on Saturday.

Some of the six crew members aboard the C-130 were killed in the crash, Lt. Col. Robert Carver said Monday afternoon, but he wouldn't say how many.

The surviving crew members were seriously injured, Carver said.

Mikeal's family said they were notified early Monday that he had died in the crash.

Mikeal, a 42-year-old married father of two from Mooresville, was a veteran of deployments to Iraq and Afghanistan.

WRAL's sister station in Charlotte, WBTV, talked to Mikeal right before his unit left.

"Adrenaline is flowing. We're ready to go," he said. "Like I said, hopefully when we get there, we'll be ready to go right when we get there and if they need us to start dropping today. We can start dropping on the fires, start helping out."

The Rapid City Journal newspaper in South Dakota reported that three people were taken to a nearby hospital after the crash.

The cause of the crash remains under investigation, Carver said.

Rescuers have reached the wreckage, authorities said Monday.

The terrain at the scene is "very, very rugged, straight up and straight down cliffs," said Frank Maynard, the emergency management director for Fall River County, S.D.

The plane was assisting in efforts to fight the White Draw Fire near Edgemont, S.D., in the Black Hills region of southwestern South Dakota, Carver said. The crash occurred about 6:30 p.m. MDT Sunday, he said.

Officials said the White Draw Fire has charred about 4,200 acres.

After the crash, the other seven firefighting C-130s were grounded for an indefinite time, Carver said.

In addition to the second plane from Charlotte, the other planes belong to the Wyoming Air National Guard, the California Air National Guard and the Air Force Reserve's 302nd Airlift Wing based in Colorado.

The N.C. Air National Guard also sent a third aircraft carrying support personnel and equipment. Carver said both of the unit's planes were shifted to Cheyenne, Wyo., on Monday.

About three dozen members of the 145th Airlift Wing were deployed in the firefighting effort.

Carver said the crews have all trained in firefighting missions, and Sunday's crash marks the first time in 40 years that a C-130 has crashed during such a mission.

"People are shaken, as you would expect them to be," he said.

The C-130s can drop 3,000 gallons of water or fire retardant in less than five seconds, covering an area a quarter-mile long by 100 feet wide. Once the load is discharged, the tanker can be refilled in less than 12 minutes.

A U.S. Forest Service official in Colorado offered sympathy to the crew members' families.

"We grieve your loss this morning along with you," said Jerri Marr, supervisor of the Pike and San Isabel National Forests, where some C-130s were fighting a wildfire last week. She didn't elaborate.

President Barack Obama and Gov. Beverly Perdue also sent condolences.

"The airmen who attack these fires from above repeatedly confront dangerous conditions in an effort to give firefighters on the ground a chance to contain these wildfires – to save homes, businesses, schools, and entire communities. They are heroes who deserve the appreciation of a grateful nation," Obama said in a statement.

"This tragic loss underscores the risks and sacrifices our servicemen and women make on a daily basis. Whether home or abroad, they leave their families to keep us safe and protect our freedom," Perdue said in a statement.

Perdue ordered all state flags to be lowered to half-staff until sunset Tuesday in honor of the C-130 crew.