Now, Luo and other nearby residents are livid at the government and want it to pay for their homes.
"I just want an answer from the government," Luo said Sunday at a protest by local apartment owners. "Are the officials corrupt, or what? Why did they build a hazardous chemical warehouse near our home without telling us? Who would want to live next to a ticking time bomb? No one!"
It's been four days since the explosions rocked the northeastern coastal city of Tianjin on Wednesday, killing at least 114 people, officials said -- with many more bodies likely trapped in the rubble. At least 57 people are still missing, according to authorities.
Rescuers have found more than 50 people alive, said Tianjin government spokesman Gong Jiansheng. They include a 19-year-old firefighter who lay on the ground for hours with burns and a cracked skull until he was found, officials said.
Workers spent another day scouring heaps of rubble for possible survivors, but one of the military commanders in the effort said Sunday that the odds of finding anyone alive are slim.
Instead, Maj. Gen. Shi Luze said, he expects the search to yield more bodies.
The blasts, one of which had the force of more than 20 tons of TNT, left more than 700 people injured and thousands homeless, officials said.
Residents worried about lingering contamination.
"I asked my in-laws to take my daughter home. I don't want them to stay here," migrant worker Tian Binyan said. "I'm worried. I heard it's going to rain later, and that would make the air toxic."
Like Luo, Zhang Yuqin wants the government to buy out her home near the warehouse. She wears a surgical mask while outside, as do several other protesters.
"We haven't been back home since the explosions," Zhang said. "The soldiers wouldn't let us into the compound. We heard they're cleaning up our homes. We haven't agreed to it, and don't know why they're cleaning up."
'Lessons paid for with blood'
Chinese President Xi Jinping said Saturday that the Tianjin blasts and other recent accidents exposed severe problems in workplace safety.
He urged authorities to heed "safe growth" and the people's interest first in efforts to avoid such accidents, the state news agency Xinhua reported.
The president also "urged authorities to learn from the 'extremely profound' lessons paid for with blood" in the Tianjin explosions, Xinhua said.
Xi is demanding improvements to workplace safety, the agency added.
The chemicals in the warehouse
The warehouse was a temporary storage facility that housed materials after they arrived at the port and before they were transported elsewhere, said Gao Huaiyou, deputy director of the city's Work Safety Administration.
The warehouse was destroyed by the explosions, he told reporters, and managers of the facility have provided "insufficient information" about what chemicals were stored there.
But sodium cyanide, a highly toxic chemical that can kill humans rapidly, was one of them, Gao said.
On Sunday, Shi, the military commander, offered more details about what was at the site.
"After on-site inspection, we have found several hundred tons of cyanide material at two locations," he said.
"If the blasts have ripped the barrels open, we neutralize it with hydrogen peroxide or other even better methods. If a large quantity is already mixed with other debris, which may be dangerous, we have built 1-meter-high walls around it to contain the material -- in case of chemical reactions if it rains. If we find barrels that remain intact, we collect them and have police transport them to the owners."
The environmental group Greenpeace, citing a local monitoring station, said it believed other dangerous chemicals stored at the site included toluene diisocyanate and calcium carbide.
Gao said further investigation, including checks of customs records, would be needed to establish the types and amounts of all the chemicals at the warehouse.
The environmental toll
More than 2,000 troops are searching areas within a 3-kilometer radius for hazardous material that may have been blown out by blasts, Shi said.
Wen Wurui, Tianjin's environment protection chief, said Thursday that some chemical levels in the area were higher than normal but they would not be dangerous to humans unless someone were exposed to them for long periods.
By Sunday, toxin levels at the site had dropped to normal and won't cause any health hazards, Shi said.
And Bao Jingling, chief engineer of the Tianjin Environmental Protection Bureau, said the air and water are safe for residents.
But Greenpeace warned that rain could pose more challenges by setting off reactions and washing chemicals into the ground.
Searching for a cause
Fire officials said hazardous chemicals stored at the warehouse were ignited by fire. But the cause of the fire has yet to be determined.
Executives from Rui Hai International Logistics Co., the company that owned the warehouse, have been taken into custody, state media reported Thursday.
The warehouse is in a sparsely populated district about 40 kilometers (25 miles) from the center of Tianjin, a sprawling metropolis of more than 13 million people.
About 90,000 people live within a 5-kilometer radius of the blast site, the China Earthquake Networks Center said.