An off-duty Singapore Civil Defence Force (SCDF) officer has won praise for leading the rescue of a 20-month-old boy who accidentally locked himself inside a lorry on Sunday.

Senior Warrant Officer (SWO) Hasanuddin Johar, 52, was visiting his daughter's home in Woodlands with his wife and son when he heard a commotion from the open carpark at Block 302A, Woodlands Street 31. He later found out that a child was trapped inside a lorry in the carpark.

"My dad, being a fire officer, went over to provide assistance. He didn't jump in straight away," SWO Hasanuddin's son Muhammad Noor Affiq, 27, a PhD student, wrote in a Facebook post about the rescue.

"Rather, he observed from afar to assess the situation before coming up with the best solution to tackle the problem without causing too much damage to the lorry."

SWO Hasanuddin was soon up on top of the lorry's cab section, armed with "metal bars and other things" to prise open the door, Mr Affiq added. "With teamwork and effective communication, the young boy was finally freed and returned to his parents. My dad, the hero."

The Straits Times understands that the rescue took about 15 minutes.

Mr Affiq's post, which included two photos of his father taking part in the rescue, has been shared more than 1,000 times since it was put up on Sunday afternoon.

Speaking to The Straits Times yesterday, SWO Hasanuddin downplayed his contribution and said the rescue would not have been possible without the efforts of the boy's family members and several members of the public.

Singling out a Chinese man who had helped him prise open the lorry door, the regimental sergeant- major with the 4th SCDF Division said: "It was heartening to see so many people of different races pitching in to help."

He said he decided against breaking the lorry's window as there was the risk of the shattered glass injuring the boy within the confines of the lorry cab. Even though the boy was crying, the air-conditioning in the lorry was on and his family did their best to placate him with YouTube videos.

"I understand this was an accident. The boy had dropped something outside the lorry and his parents had alighted to retrieve it," he said.

SWO Hasanuddin, who has been with the SCDF for 34 years, was lauded by the SCDF in a Facebook post. "As the saying goes, a true firefighter is never off duty... A classic example of #CommunityFirst- Responders in our midst - keeping a watchful eye on the safety of others wherever they may be," the post said.

"We need more #Community FirstResponders like Encik Hasan!"