After only a year in Bandung, Lasut decided not to become a teacher and instead moved to Batavia (now Jakarta) to attend an Algemene Middelbare School (AMS) .

He then applied for and was given a scholarship to become a geological assistant at the Mining Service (Dutch: Dienst van den Mijnbouw).

While at technical school in Bandung, Lasut was trained as a Corps Rerserve Officer by the Dutch to aid in the defense against the attacking Japanese forces.

[4]: 196  As the Dutch returned to regain its control of Indonesia, the offices of the Mining and Geological Service had to be moved several times.

[5]: 171  In addition to managing the mining and geological activities of the new nation during an unstable period, the service also established schools for training new geologists.

[7]: 119  On the morning of 7 May 1949, Lasut was taken from his home by the Dutch to Pakem, 7 kilometers north of Yogyakarta (then the capital of Indonesia) and was shot to death.

[1] To honor his firm stance to preserve the republic, Arie Frederik Lasut was posthumously named a national hero by President Suharto on 20 May 1969.