THEY SERVED IN SILENCE

Cryptologic Service and Sacrifice

SP5 Carl H. Caccia USA SP5 Robert J. Potts SP5 Mitchell B. Smith SP5 Robert J. Thelon

For most of the personnel serving with the Army Security Agency’s (ASA) 404th Radio Research Detachment, 

February 21, 1971 was shaping up to be a routine day. The weather was tolerable for Vietnam that time of 

year, bright sunshine, a light wind and a comfortable 73 degrees. Based at Landing Zone English in Binh Ding 

Province, the unit’s mission was to provide and protect critical communications for the 173rd Airborne Brigade. 

Since April of 1969, the 173rd had been engaged in heavy fighting in the area, and the intelligence culled by the 

work of the men of the 404th had increased the odds of victory on the battlefield, and saved lives. 

At one point during the day, four members of the unit headed out in a jeep on a routine supply run. All of them 

were in their early twenties. It was to be short trip, and they were not expecting to be gone long.

Driving the vehicle was SP5 Carl Caccia. A native of Detroit, Michigan, Caccia was the unit supply specialist, and 

during his tenure he had acquired a reputation for industriousness and dedication to the mission. According to 

the schedule, this was to be one of his last supply runs. His time “in country” was coming to an end. He was due 

to leave Vietnam in four days. 

SP5 Robert J. Potts hailed from Baltimore, Maryland, made his living as a communications center specialist, and 

was on his second tour in Vietnam. Potts loved animals and was the owner of Datko, the unofficial canine mascot 

of the unit. He was also engaged to be married. 

Mitchell B. Smith was a native of Takoma, Washington. Trained as Morse intercept operator, 

he had been in Vietnam since October of 1970. A unit photo of him standing in front of a jeep 

brandishing a weapon and grenades suggested that he was comfortable in the field as well as 

in the intercept shack. 
MP 33610

SP5 Robert J. Thelen hailed from Fowler, Michigan. Thelen was a highly skilled and experienced ASA intelligence 

specialist but in addition, due to his previous training, he wore the Green Beret of the US Special Forces. He had 

been in Vietnam since June of 1970. 

On their return from the supply depot, the group ran into a full-fledged enemy ambush. Official records state that 

the vehicle struck a mine, but others noted that when they arrived on the scene there was strong evidence that 

the men had also been subjected to heavy rocket and small arms fire. All perished in the attack. 

The deaths of the four men left many understandably saddened and heartbroken. Carl Caccia’s parents could 

not bear to look at the “welcome home” banner they had put up at the front of Carl’s childhood home. They had 

expected him home in a few days. Their son was buried in Mount Olivet Cemetery in Wayne County, Michigan.

Robert Pott’s fiancé remembered him as “a gentle loving man that I hold in my heart always.” Robert is buried in 

Loudon Park Cemetery in Baltimore, Maryland.

Jack D. Wyatt, a fellow soldier, in honoring Robert Thelen, noted that “We will never forget you, Bob. You were 

the best of the best. . .” Robert is buried at St. Mary’s Cemetery in Westphalia, Michigan. 

A fellow soldier and friend of Mitchell Smith related that Smith “would never be forgotten,” and that Mitch’s 

laughter would forevermore “ring in heaven.” Mitch is buried in Fir Lawn Cemetery in Pierce County, Washington. 

The lives of the four dedicated soldiers demonstrated that while cryptologic work can often be performed in 

safe, secure surroundings, the stark reality is when nations go to war those who provide and protect critical 

information must often place themselves in harm’s way, often with devastating consequence. It is in this spirit 

that we honor and remember their indelible service and ultimate sacrifice to and for their nation.