To 1947, being suffered heavy losses in the Bien Gioi, Viet Bac operations, the strategy of fast fighting and fast win did fall down, French colonialists with the plot of using Vietnamese rules Vietnamese, did involve and bride reactionary, sow division and oppose the revolutionary government.            

Knowing the enemy’s strategy, The Central Intelligence Services did send Hoang Dao to penetrate and got steady position in the Bao Dai’s government as Secretary of State. To control easily, French colonialists did offer sending the Amyot D’Inville battle ship, one of the biggest dispatch vessel to take the Secretary of State Hoang Dao’ wife to Hanoi.   

            To realize that this is a favourable opportunity, The Central Police Service did decide to bomb Amyot D’Inville. Thanh Hoa and Hanoi Intelligence Agencies were entrusted with this important task. Miss Nguyen Thi Loi, Thanh Hoa police woman did volunteer to do this task.  

Acting Secretary of State’s wife, in the night of 26^th September 1950, Nguyen Thi Loi (code number A16) get into Amyot D’Inville. Giving health as a pretext, the Secretary of State’s wife get in the room with 30kg of explosive containing in a suitcase which the French colonialists thought as opium. Around 30 minutes later, the Amyot D’Inville battle ship did blow up with more than 200 French officers and hundreds tons of explosive which the French colonialists was going to support the French armed forces in Vietnam and made the plot of the French colonialists fail completely.

This event is considered as an important point in the Vietnamese history, one of several resounding victories of the Intelligent force of people’s police forces in general and Thanh Hoa in particular at the beginning, made contribution to the success of the national protracted resistance war.   

 On the 3^rd August 1995, The Vietnamese state did bestow posthumously title “Heroine of The people’s armed forces” to Nguyen Thi Loi agent.