Mr Dai Guanchao looks nervously at the mountain of sand towering menacingly next to his home. It dwarfs a lone excavator at work in the stone quarry as heavy machinery churns away in the background.
Only a simple fence separates the Shuijing stone quarry from Mr Dai's apartment complex, Qingqing Jiayuan, in Shenzhen's eastern Longgang district.
In the past year, Mr Dai could only watch as the sand piled up to a height of more than 20m. Following the Dec 20 landslide, he is increasingly worried that something similar may happen in his area.
"Sometimes I come by just to watch them work, I want to know what they are doing especially with the landslide that just happened," Mr Dai, 59, told The Straits Times. "I think it's very dangerous to have such a huge sand pile next to a residential area. It seems like an accident waiting to happen."
Jitters remain almost two weeks after the landslide at a soil dump site sent tonnes of mud and construction debris spilling onto factories and dormitories, toppling or burying many of them.
At least seven people have been killed and more than 70 are missing in what the authorities have described as an "industrial accident".
Truth be told, we don't know what is going on there so it's a little frightening. We used to see many soil trucks turning into the site, causing traffic jams, but that has stopped since the landslide.
MR ZHOU GUOHUA, who lives in a housing estate about 1km away from a construction dump site in Nanshan district
This is hardly reassuring to residents like Mr Dai amid reports that other sites in the city may also pose safety risks. His apartment building is closest to the quarry site.
Complaints were made against the site owner in the past when the explosives used in quarrying shook buildings in the area, said another resident, Madam Chen Sihui, 45. But no action was taken.
"Back then, the explosions were so violent that the tea cups on our table would rattle, but despite our feedback to the authorities on the safety risk this posed, nothing was done," she told The Straits Times.
"We never considered the danger of living so close to a quarry in the past but with the recent developments, of course it's now on our minds," Madam Chen added.
At another construction dump site on Tanglang hill in western Nanshan district, residents of the nearest housing estate about 1km away also expressed growing fears.
"Truth be told, we don't know what is going on there so it's a little frightening. We used to see many soil trucks turning into the site, causing traffic jams, but that has stopped since the landslide," said Mr Zhou Guohua, 35.
"We have a sense of security as we can't see the landfill but looking at the scale of the recent disaster, we might not be out of harm's way should a similar accident happen."
A security guard turned me away when I tried to enter the Tanglang site, saying it was a "sensitive time".
Local media reports say the district's chief had already inspected the site. Officials were also quoted as saying the landfill owner took safety measures such as building rammed-earth walls at the foot of the hill to prevent landslides. It also compacted the soil brought in and built drainage pipes to prevent a run-off during a downpour.
But the disposal of construction waste remains a widespread problem in urban areas as China's frenetic building leaves behind a growing mountain of debris, experts say.
Shenzhen, in particular, a former fishing village that has prospered since it was picked more than three decades ago to pioneer landmark economic reforms, has been a hallmark of this breathless sprint.
Yet management of construction waste has long lacked legal and official supervision, with most construction waste randomly dumped in suburban areas, experts add.
"Dumps and recycling sites usually don't feature in urban planning programmes or city budgets," Professor Chen Jialong from Beijing University of Civil Engineering and Architecture said in a China Daily report. "About 50 per cent of cities have still not drafted any rules."
Mr Song Ding, director of real estate research at the China Development Institute think-tank, noted the lack of clear rules like how close residential areas can be to such sites. "But this is a huge wake-up call and with President Xi Jinping pledging to make cities safer, new rules are likely to be in place soon," he told The Straits Times.