The boy said that his parents would reward him with a new toy if he sold all the tofu.
Some vendors even record themselves digging up the dirt to prove its authenticity.
An investigation is underway to determine the motive behind the father's actions.
The 76-year-old was charged with 13 offences and pleaded guilty.
Tiles usually pop due to changes in weather temperature or age, said MP Alex Yam.
The municipality later sent a vehicle to drain the sewage and assist with the clean-up.
She was last seen in a long-sleeved white shirt, a black hijab, and black trousers with a backpack.
Among those arrested was a 17-year-old boy.
The building involved in the collapse, constructed in the 1970s, may have used lower-quality materials than modern buildings.
A man on the road could be seen barely avoiding getting run over by the lorry.