FAIRCHILD AIR FORCE BASE, Wash. -

Fairchild Air Force Base held a special retreat ceremony Tuesday to remember the four airmen lost in the B-52 crash at the airbase 20 years ago.

The retreat is held in memory of Col. Robert Wolff, Lt. Col. Arthur Holland, Lt. Col. Mark McGeehan and Lt. Col. Kenneth Hutson, who were killed in the crash of Czar 52 on June 24, 1994. The air crew was practicing for an upcoming air show when the aircraft banked past 90-degrees, lost lift and plummeted to the ground in a massive fireball.

The Air Force investigation blamed the accident on the pilot, Lt. Col. Arthur Holland, who had been practicing unauthorized and unsafe maneuvers.

The crash came just four days after a deadly rampage at the base hospital where several people were killed and more than a dozen were wounded.

Gary Clark was friends with all four men and attended today's memorial .

He says its a time in his life he won't forget, vividly remembering the four men who were killed that afternoon.

"Absolutely marvelous people as far as there jobs and what they did and what they stood for," Clark said.

Clark says he was suppose to be on the Czar B-52 that day but was traveling from Texas to Canada with his wife.

"It was very difficult," Clark said. "It was difficult on everybody and the people that stayed here."

Base commander Colonel Brian Newberry said marking these anniversaries is important and added the memories of the four airmen killed in the crash won't be forgotten.

"For me as a leader I need to remember those that we lost and I also need to take inspiration from what those airman did by moving forward," Newberry said. "We never leave and Airmen, Soldier, Sailor, or Marine behind. Part of not leaving somebody behind is remembering them. That's what we did today. We will remember."