THEY SERVED IN SILENCE

The Story of a Cryptologic Hero

SP4 Jeffrey W. Haerle

There are only two dates out of the 716 days I spent in RVN that I 

remember: 0245-31 January 1968, the minute that the Tet began, and 

13 May 1968.

 Buck Buchanan, Former ASA Radio Repairman

SP4 Jeffrey W. Haerle was born on May 23, 1946, in St. Louis Park, Minnesota, 

a suburb of Minneapolis. As a young man, Jeff loved baseball playing at both 

the Little League and Connie Mack levels of the game. He graduated from St. 

Louis Park High in 1964, and shortly after, joined the United States Army. After basic and advanced training, 

he was assigned to the 509th Radio Research Group. 

The 509th was part of the Army Security Agency (ASA), the cryptologic element of the US Army during 

the Vietnam era. In time he became part of the 372nd Radio Research Company (RRC), a sub-unit of 

the 509th. Originally based in Okinawa, Japan, in 1966, the unit was sent to Tay Ninh Province to support 

the 25th Infantry Division (25th ID). The Tay Ninh region lies in the southeast corner of South Vietnam, a 

little over 60 miles from what was then the capital city of Saigon. Like all ASA units, Jeff and his fellow 

cryptologic professionals were dedicated to gathering the critical intelligence to allow US and coalition 

forces to gain an advantage in the battle space, and ultimately to save lives. 

In May of 1958, Jeff was stationed at the Nui Ba Dinh listening post located at the top of a boulder-strewn 

peak. Known as the Black Virgin Mountain, due to a legend of a young Vietnamese girl who in despair had 

thrown herself off its highest precipice, it was a site that had been of strategic value to the Japanese and 

French in past times. In addition to the cryptologic personnel assigned to the post, the area was defended 

by a company of 25th ID soldiers and Green Berets. Despite its seemingly remote location, Nu Ba Dinh 

was vulnerable. In the words of a prominent author on the ASA during Vietnam, “The Americans held the 

very top of the mountain, but the 3000 feet of crags, crevices and caves that constituted the sides of the 

terrain feature belonged to the Viet Cong.” 

The evening of May 13, 1968, began calmly. The post had only been in operation for a week prior but 

everyone had settled in and established routines. Two assigned personnel were busy at work in the main 

operations area referred to as “The Pagoda.” The rest of the cryptologic cadre, including Jeff, had been 

released for the evening and were headed either to the barracks or the mess hall. No one was expecting 

an attack.

At 2145, a group of Green Berets were watching TV when they were interrupted by a 

series of loud booms. Assuming it was a local mortar crew training with illumination 

rounds, they ignored them until a barrage of shrapnel hit the building. What would come 

to be known as the “Nui Ba Dinh massacre” had begun. The sappers wasted no time 

overwhelming the base defenses, and enemy rocket-propelled grenades and mortar 

rounds filled the air. Some soldiers managed to retreat to defensive positions, but the 
MP 233610

attack had been so swift that the majority of the men had not even had time to get dressed, and were 

forced to try to find cover wherever they could. 

Trapped under the fiery barracks with another soldier, Jeff related that he had no intention of burning to 

death, and made a run for the Pagoda. As he attempted to quickly move to a large rock for cover, he was 

killed by enemy fire. By the time the attack concluded at 2330, twenty-four men, Haerle among them, 

had fallen prey to the onslaught. In addition, thirty-five men were wounded and one was taken prisoner 

during the attack.

Like so many soldiers, SP4 Jeffrey T. Haerle died before his time. He had only been in Vietnam for 28 

days and was ten days short of his twenty-second birthday. He was remembered fondly by his those 

who knew him and worked with him. A fellow soldier recalled that “I was fortunate to serve with Jeff on 

Okinawa at Torii Station ... I wished him a safe return the day he left. Rest in peace Jeff, you were a brave 

and true friend.”

Jeff’s body was returned to his Minnesota home and laid to rest in Ft. Snelling National Cemetery, next 

to the military installation for which it was named. The fort was stood up in 1819 in order to protect the 

western frontier of the United States. In that tradition, Jeffrey had paid the ultimate sacrifice in helping his 

nation defend freedom in a different part of the world. It is in this spirit, and in his memory, that we honor 

his supreme service and sacrifice.