"I asked my in-laws to take my daughter home, I don't want them to stay here," migrant worker Tian Binyan told CNN. "I'm worried. I heard it's going to rain later and that would make the air toxic."
She was among the 6,000 or so displaced by the fire and explosions that rocked the port Wednesday night, sending huge fireballs and plumes of smoke into the air.
The blasts, one of which was the equivalent of more than 20 tons of TNT exploding, left at least 85 dead, more than 700 injured and thousands homeless, officials say.
Zhou Tian, chief of Tianjin Public Security Fire Bureau, told reporters Friday evening that the flames have been largely extinguished on site, but some smoke remains.
So do the questions, despite assurances from authorities.
What chemicals did the warehouse store?
Tianjin officials say they are unable to give a detailed list of exactly what chemicals were being stored at the warehouse.
Gao Huaiyou, the deputy director of the city's Work Safety Administration, said Friday the warehouse was only a temporary storage facility. Materials were kept there briefly when they arrived at the port and before they were transported elsewhere.
The warehouse site was destroyed by the explosions, he told reporters at a news conference, and managers of the facility have provided "insufficient information" about what was stored there.
Sodium cyanide, a highly toxic chemical that can rapidly kill humans exposed to it, was one of the materials, Gao said.
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 try to establish the types and amounts of the chemicals at the warehouse.
What is the environmental toll?
Chinese officials have sent chemical and biological experts to the scene, and some 1,000 firefighters are still at the ravaged site, pouring foam and sand on lingering hotspots, according to authorities.
Wen Wurui, Tianjin's environment protection chief, said Thursday that some chemical levels in the area were higher than normal but that they wouldn't be dangerous to humans unless someone is exposed to them for long periods.
And environmental officials said that they've found nothing unusual in the waters off Tianjin, state media reported.
Still, the worries persist.
Greenpeace warned that the possibility of rain Friday could pose more challenges by setting off reactions and washing chemicals into the ground.
Liu Yue, a 25-year-old who lives about 4 kilometers (2.48 miles) from the blast site said she and others were taking precautions against possible contamination.
"I've told my parents not to drink tap water," she said.
What caused the blasts?
Fire officials say hazardous chemicals stored at the warehouse were ignited by fire. But the cause of the fire has yet to be determined.
Officials didn't address the issue directly at the news conference Friday morning.
Executives from Rui Hai International Logistics Co., the company that owned the warehouse, have been taken into custody, state media reported Thursday.
Lei Jinde, an official from the Chinese Public Security Ministry's firefighting bureau, told thepaper.cn, a Shanghai-based newspaper, in a telephone interview that the first team of firefighters used water in an attempt to contain the fire. It was necessary to cool the blaze, he said, according to a CNN translation.
But water isn't the best fire suppressant for some chemicals.
Calcium carbide reacts with water to form acetylene, which can catch fire.
"We knew there was calcium carbide inside (the warehouse), but no one had knowledge if it was exploding or on fire," Lei said. "It's not that the firefighters were stupid that they would still use water (to put out) after knowing there was calcium carbide. I didn't mean that. We absolutely can't say it was wrong to use water."
Authorities in Tianjin appeared to have been concerned recently about the handling of hazardous materials at the port.
A notice posted by the Tianjin Administration of Work Safety on its website last week said city officials held a meeting with executives of more than 20 companies that handle dangerous chemicals at the port.
The agency's director urged the executives to carry out safety management, the notice said.
On Friday, Xinhua reported that China's State Council made an emergency request to government officials to reinforce safety practices at hazardous chemical storage facilities.
How many lives did the explosions claim?
At least 85 are known dead, among them 21 firefighters, but many are still missing, including dozens of employees of the company that owed the warehouse, according to Xinhua.
One firefighter was rescued Friday from the rubble, Xinhua reported.
"I think it's his strong will which helped him to hold on," Zhang Dapeng, the chief of staff of the Bonded Zone Branch of the Tianjin Firefighting Corps said Friday.
"When talking with him, I could feel his strong inner power, and we also kept pepping him up, urging him to hold on and telling him the ambulance was arriving," Zhang said.
Things could have been even worse if the explosions had come during the day, when more people would have been working in the port area.
The district where the warehouse was located is thinly populated. It's roughly 40 kilometers (25 miles) from the center of the city, a sprawling metropolis of more than 13 million people. About 90,000 lived within a 5-kilometer radius of the blast site, the China Earthquake Networks Center said.
More than 6,000 people have taken shelter in a dozen nearby schools and three apartment compounds, said district official Zhang Ruigang, after their homes were damaged by the explosions' shock waves.
Amid a camp of tents on the grounds of one school, Tao Shunfeng recounted driving a truck through the port when the explosions struck, shattering all the vehicle's windows.
He said he was now worried about the air and planned to leave Tianjin with his wife and child to return to his home province of Henan.