Naib Subedar Gurnam Singh was born on 18 August 1935 in Bhullar village, Amritsar district, Punjab, to Shri Teja Singh. He came from a family with a military background and joined the Indian Army, serving with the Bombay Sappers and the Corps of Engineers.
During his military career, he served with engineering units including the 22 and 23 Field Companies and later became an instructor at the College of Military Engineering, Pune. He developed expertise in mine-clearing techniques and was regarded as an experienced instructor in the field.
On 23 September 1973, a mine-clearing demonstration was organised at the College of Military Engineering for visiting staff and student officers of the Defence Services Staff College, Wellington. Naib Subedar Gurnam Singh was responsible for conducting the demonstration of a Charge Line Mine Clearing system with the assistance of seven sappers.
During preparations, the explosive charge was prematurely activated. Realising that the men under his command were in immediate danger, he ordered them to move away from the area. He then attempted to make the activated charge safe, placing his own life at risk. The explosion occurred before he could neutralise it, and he was killed.
For his exceptional courage, leadership and devotion to duty in sacrificing his life to protect his men, Naib Subedar Gurnam Singh was awarded the Ashoka Chakra posthumously.