Regular shoppers at Jurong Point's FairPrice Xtra will be familiar with the rumbling rattle of trolleys accompanied by a loud voice yelling: "Hello! Excuse me!"
It is that of Mr Tan Ngee Tong and his team, known as "trolley boys". But it is not just in the store that they can be heard.
Every day, these supermarket staff, wearing gloves and trainers, go around the mall's vicinity searching for lost trolleys and returning them to the store in Boon Lay.
Some of these trolleys are left by shoppers at taxi stands, carparks and even the surrounding housing estates.
Mr Tan, 31, and his colleagues retrieve over 100 trolleys every day.
We have collected trolleys from as far as Lakeside and Pioneer before. Once, we found a row of trolleys in a canal drain.
MR TAN NGEE TONG, a trolley boy at Jurong Point's FairPrice Xtra, on how far he and his team have to sometimes travel to retrieve lost trolleys.
The trolley boys typically work in eight-hour shifts and sometimes, they find carts several kilometres away. "We have collected trolleys from as far as Lakeside and Pioneer before," said Mr Tan, a trolley boy of five years. "Once, we found a row of trolleys in a canal drain."
Some shoppers even use chains to lock up these trolleys outside their flats. In videos sent in by a Straits Times reader, Mr Tan and his colleagues can be seen wheeling long rows of trolleys across a road back to Jurong Point.
These long-distance trips are physically demanding, as some roads can be bumpy, and the sheer number of trolleys makes them hard to manoeuvre. The job has even resulted in injuries.
"We shout out warnings, but some pedestrians don't hear us approaching because they are wearing earphones," said Mr Tan. "So we protect them by using our bodies to block the trolleys, but end up with bruises and aching legs."
A FairPrice spokesman said trolley retrieval staff start as early as 7am and end as late as 11pm. Each store retrieves about 50 to 150 trolleys a day. The farthest stray cart was found more than 2.5km away.
Supermarkets have long grappled with the problem of missing carts, which can result in hefty losses.
FairPrice has lost about 1,000 trolleys annually in the past two years. It spends an estimated $150,000 on repairing, replacing and retrieving trolleys each year.
Last year alone, Sheng Siong lost about $120,000, with an average of 180 trolley baskets and 90 trolleys going missing each month.
Dairy Farm Group, which runs Giant and Cold Storage, had said its Giant supermarket in Jurong East lost 600 trolley baskets last year.
The chains have tried to stem the problem through public education. FairPrice puts up signs and plays pre-recorded messages in stores to remind customers to return these trolleys. Sheng Siong's cashiers also remind customers to push their carts back to the stores.
But the efforts have had little effect, even though some customers have tipped off the supermarkets on the location of missing trolleys.
"The situation is not improving. More people seem to be dumping trolleys elsewhere," said Mr Tan. "Maybe it is because now you only need 50 cents to borrow a trolley, instead of $1."
Human resources executive Linda Chua, 50, said she sees as many as five abandoned trolleys every day at her void deck in Jurong West.
"It is not responsible. The trolleys are just a loan of convenience. We should return them instead of taking advantage of the stores."