He wrote a popular song which he would sing and it is said that he died singing it:

"Sewa desh di jinddhiye badhi aukhi
gallan karnia dher sukhalliyan ne,
jinha desh sewa 'ch pair paya
ohna lakh museebtan jhalliyan ne."

Serving ones country is very difficult
It is so easy to talk
Anyone who walked on that path
Must endure millions of calamities.

The judgement in respect of 63 arrested Gadharites was pronounced on September 13, 1915, at the Central Jail, Lahore. In this first conspiracy case of 1914/15 AD, 24 Gadarites were sentenced to death. Kartar Singh was one of them.

The court observed that Kartar Singh was the most dangerous of all the rebels. "He is very proud of the crimes committed by him. He does not deserve mercy and should be sentenced to death". Kartar Singh was hanged in the Central Jail of Lahore on November 16, 1915, when he was only 18.