"I'd promised to send him to a swimming centre once his exams were over but didn't realise how important it was," she said, recalling the day in 2011 when Amanto, 14, went to play in a nearby canal and never came home.
"Now there can be no doubt how important it is... I don't want any mother to suffer the agony I've been through."
Around 18,000 children drown each year in Bangladesh -- a daily average of just over 49 -- making it the leading cause of death among children aged one to 17.
But few youngsters can swim, as most parents are reluctant to pay for lessons while struggling to make ends meet in one of the world's poorest nations.
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But earlier this year, the government announced it would make it mandatory for all schoolchildren to learn to swim, making it the most ambitious mass swimming programme ever attempted.
While other countries such as Australia have made swimming lessons compulsory, the scale of Bangladesh's plan is unrivalled -- no country has ever set itself such a large target and it is expected to be several years before every youngster takes the plunge.
"I believe it is the biggest swimming programme to have ever been conducted at one time."
Given the shortage of proper swimming centres, the government has ordered schools to use local ponds as an alternative while the UN's children's fund UNICEF is making giant inflatable pools available along with helping to fund or run some of the lessons.
On a chilly Sunday morning in the capital Dhaka, a group of around a dozen boys and girls were taking a dip in one of the UNICEF pools, just about able to stand in the four feet of water.
Amy Delneuville, a UNICEF child protection specialist, said trainers had received a warm reception, including in conservative rural areas where the idea of girls in swimming costumes might have been frowned upon.
"As there are so many water bodies in Bangladesh, drowning for children is a very serious issue here," she told AFP.
"People are very happy with the programme. They know how dangerous water can be."