During the Indo-China war of 1962,the 1/8 Gorkha Rifles was deployed in Chusul to protect Chusul airfield, On 21st October, the Chinese subjected the "C" company holding the outpost of Shirijap to heavy artillery and mortar fire, damaging the company's wireless system in the process.

As communicationswas cut off and nobody at the base knew what was happening at sirijap, Naik RabiLal Thapa volunteered to go and find out. He had to cross a river so he went by boat. When he was about 1000 meters away from Sirijap,the enemy spotted him and began firing.Thapa's boat was hit but he managed to return base with vital information about the enemy position around Sirijap.That same evening, Thapa again endangered his life by undertaking in two boats, the evacution of another threatened post. The boats came under heavy fire. Even as one boat began sinking, Thapa went to the rescue of the drowning men and saved several lives.

Lance Naik Thapa was awarded the Mahavir Chakra for his exceptional courage.