Lieutenant Lina Chan Kobayashi was eating with her grandmother in a ramen shop in Tokyo when the 2011 earthquake struck - shaking walls and sending wooden menu boards flying.
TV images she later saw of the Fukushima nuclear disaster and of victims who lost their homes and families made her want to go to the disaster zone to help - however, she did not possess the skills and training she has now.
Yesterday, the 24-year-old and 42 other cadets from the Singapore Civil Defence Force (SCDF) 13th Rota Commander Course were commissioned as officers.
She told The Straits Times how her experience in Japan, where she had been visiting her Japanese relatives, inspired her to join the SCDF.
"It got me thinking, what if that was my family?" she said.
"I called my dad and I told him I wanted to go down to the disaster area to help, but he said 'no, you'll just be a liability'."
Lt Chan, who is qualified in cardiopulmonary resuscitation and first aid, was in the pioneer batch of the National Civil Defence Cadet Corps (NCDCC) at her secondary school when it was introduced in 2005.
The overall top cadet was Captain Koh Guan Chong, 24, who was awarded the Home Team Local Study Award to complete his studies at the Nanyang Technological University last year.
Capt Koh said he was inspired to join the SCDF after helping a lifeguard save a drowning woman at the Jurong East Sports Complex swimming pool in 2013.
"She thanked me repeatedly afterwards, and I felt that the sense of fulfilment from my simple act was really great," he said.
Other top-scoring cadets include full-time national serviceman Rahul Swaminathan, 19, who was the overall second-best cadet, and also won the Best in Theory and Best NSF awards.
Lt Rahul, an Indian national and permanent resident, first moved to Singapore in 2001.
"At first, when I was selected for SCDF during Basic Military Training, I was quite shocked, but I'm really happy that I have a chance to save lives during my NS," he said.