Sixteen airmen from the Air National Guard's 145th Airlift Wing based in Charlotte are in California to fight wildfires there.

They left from Charlotte-Douglas on Monday morning, about six weeks after four of their fellow airmen died in a plane crash on the same mission in South Dakota.

Some who left Monday morning were also on the South Dakota mission, but they were not involved in the crash.

Eyewitness News was there as the airmen loaded up the C130s and performed preflight checks the same way some of them did six weeks ago. But this time was different.

"It's an emotional time for all of us," said Lt. Col. Kevin Harkey, the pilot on one of the planes that left.

In California, they will spray fire retardant and water on wildfires there through early September.

Harkey said he's ready for the mission but will be thinking of the four men who died, men he called dear friends.

"Their spirit is going to continue to live with us and one of the driving forces for me today is to go out and continue living their legacy,” he said.

Harkey has a wife and young children just like those who died. They're used to him deploying, but he said there were several conversations around the dinner table about this trip.

"Our faith in God and everything we believe in will get us through," he said.

This unit is one of just four in the country that can fight wildfires. The work involves flying low at low speeds, through heavy smoke and drastic temperature changes.

"It's extraordinarily challenging flying. These people are highly trained, highly skilled, they've been at their positions for thousands of hours," said Lt. Col. Robert Carver from the Air National Guard.

The cause of the crash six weeks ago is still under investigation. Investigators have been on the base in Charlotte interviewing a number of people in recent weeks. There's no word yet on how long the investigation may take.

Two men who were seriously injured in the crash recently got out of the hospital, but we're told they have several months of recovery and counseling ahead of them.