Children often play at the multi-storey carpark in Pasir Ris where a girl is believed to have fallen to her death on Wednesday, said residents in nearby HDB blocks.
They said children, who are mostly unsupervised, make the most of the empty upper levels.
A 28-year-old resident said children in school uniforms usually cycle around the top floors late on weekday afternoons.
Another resident, five-year-old Summer, told The Sunday Times that she had cycled there with her younger brother.
Other residents said older students sometimes practised parkour on the rooftop garden and people would congregate in groups on the upper levels at night.
Carlyn Wee, a 13-year-old from Hai Sing Catholic School, was found motionless at the ground level of the carpark at Block 526B Pasir Ris Street 51 at about 4pm on Wednesday.
She was later pronounced dead.
Chinese-language newspaper Shin Min Daily News reported that Carlyn was believed to have lost control of her bicycle while cycling down a ramp on the sixth level of the carpark.
She was said to have collided into a metre-high rail on the side wall before falling from the building.
Shin Min said a domestic helper who spotted the girl lying at the foot of the carpark after hearing a loud noise called the Singapore Civil Defence Force and the police.
Only the two lower levels of the building were occupied by cars when ST visited on Friday at 11am and 6pm. There were just two motorcycles on the sixth level.
The carpark has six levels and a rooftop garden.
Carlyn was cremated yesterday morning at Mandai Crematorium.
Shin Min reported that more than 30 people were present, including 10 who were believed to be her classmates.
A relative, who did not wish to be identified, told Shin Min that Carlyn was a sensible and cheerful girl and the only child in her family.
The relative also urged parents to pay more attention to the safety of their children and inculcate in them a greater awareness of their own safety, so as to prevent future accidents of a similar nature from happening.
Police are investigating.