Two people were rescued early Wednesday morning after being buried for more than 60 hours, state-run news agency Xinhua reported.
One survivor, a man from Chongqing in central China, has been identified as Tian Zeming. The second person later died.
It took three hours from when Tian was first located until he was pulled out. Firefighters had to squeeze into the narrow space around him and remove the debris trapping him with their hands, Xinhua reported.
Rescue worker Wang Yahui told state broadcaster CCTV that Tian may have been able to survive thanks to a beam that held up some space -- a narrow 40-centimeter oxygen passage -- after the building collapsed.
He was transferred to a hospital and underwent surgery for his injuries. He is extremely weak at the moment and is suffering from severe dehydration, the hospital president told CCTV, but is stable.
There was grim news, however. Four bodies were pulled from the red mud and rubble, Xinhua reported.
At least 16 people remain hospitalized -- three in serious condition, according to Shenzhen's emergency response office.
Likelihood of survival small
A massive rescue effort involving 4,000 people
has been underway since Sunday's landslide, but the likelihood of finding people still alive is small, CCTV said.
CNN footage showed dozens of excavators working to clear the rubble, dwarfed by the sheer scale of the landslide, which covered 380,000 square meters (94 acres) -- or around 60 football fields.
Densely packed with few air pockets, the mud and debris were piled four stories tall in some places, CCTV reported. The landslide toppled buildings and ruptured a gas pipeline, so clearing the site could take weeks, it added.
Rescue efforts are further complicated by the soil, which is masking the smell of potential survivors, making it difficult for search dogs to find trapped people.
There are as many as 73 people reported missing, according to CNN's calculations based on Chinese media reports.
Authorities said it was hard to calculate the exact number of missing because many living and working there are thought to be migrant workers from China's poorer, inland provinces. They are often unregistered, or their relatives are far away and can't be contacted quickly.
The parents of 6-year-old Hong Laibao were delivering goods at the industrial park when the landslide engulfed factory buildings and homes.
"I want my mum and my dad to come out faster," he said, wiping tears away as he spoke to CNN from a local sports stadium being used as temporary shelter alongside his older brother and aunt.
So far, his parents are nowhere to be found.
Hong's brother described how he called his father repeatedly until his cell phone battery went flat.
"When are they going to find our parents? In our culture, no matter what happened to them, we need to see them, even if it's their remains," Hong Xianlin said.
China's Ministry of Land and Resources raised the geological disaster emergency response to level one on Tuesday, the government's highest alarm. The level applies to situations where more than 30 people died or the disasters caused a direct economic loss of more than 10 million yuan ($1.5 million).
What caused the collapse?
What exactly caused the landslide isn't clear.
The company in charge of the waste dump's construction purportedly raised safety concerns in a January report filed with the municipal government, according to the state-run Legal Evening News.
"About one million square meters (247 acres) of soil waste is left every year in Guangming New District and there's need to find its way out. Therefore it is needed urgently to build new waste dumps," the report said, according to Legal Evening News.
The report also raised the issue of soil erosion, as the dump used to be a quarry, the newspaper said.
"The area used to be a rock field; the rocks were all dug out, which created a hollow pond, so they filled the pond with mud waste, all kinds of mud waste, which turned into a giant mountain," Liu Huizhen, Hong's aunt, told CNN.
Residents had also repeatedly complained about noise and dust coming from the waste dump, local media reported.
Locals told Xinhua that hundreds of trucks carrying construction waste used to dump trash into the pile every day.
A security guard working in an area factory told Xinhua that a 250-yuan ($38) fee was charged per truck.