Chinese investigators were struggling to determine the cause of two massive blasts that ripped through Tianjin and killed a reported 104 people, as fears mounted that the fume-filled air had turned toxic.
The grim scenes of devastation in the northern port city brightened for a moment, however, when news broke yesterday morning that a firefighter had been pulled alive from the wreckage.
Mr Zhou Ti, 19, was being treated in hospital for chest injuries and was in stable condition, the city government said on Sina Weibo, China's version of Twitter.
Images attached to the post showed him lying on a hospital bed, his eyes closed.
Reddish splotches covered most of his face and there was a net bandage on his head.
SAFER TO WEAR MASKS
It's better to be safe than sorry and to take the necessary precautions, since this is a fast-changing situation.
MR WANG NING
IN GOOD HANDS
They've taken very good care of us. Everything we need, such as our daily meals, has been very well provided.
MR TONG LISHAN, 61, a retiree, saying he was satisfied with how the authorities had handled the situation so far
Mr Zhou was one of more than 1,000 firefighters sent to a burning hazardous goods storage facility in Tianjin on Wednesday.
The blasts that followed killed over 100 people, 21 of whom were firemen, and injured 720 - 25 of them critically, official media said.
CCTV reported that 13 firefighters were still missing.
Yesterday, China defended the firefighters who initially hosed water on a blaze in a warehouse storing volatile chemicals, a response foreign experts said could have contributed to the two huge blasts.
The warehouse was storing mainly ammonium nitrate, potassium nitrate and calcium carbide, according to police.
Fireman Xu Qu was one of the first at the scene of the blaze at the warehouse, but he soon noticed the water he was hosing onto the fire was not putting it out.
"If anything, it was making it bigger," Mr Xu told Reuters as he sat in a fire truck on a cordoned-off road.
He said he had no idea what was stored in the warehouse.
The State Council, China's Cabinet, said a nationwide inspection of dangerous chemicals and explosives would be launched in response to the disaster, along with a crackdown on illegal activities to strengthen industrial safety.
A team of 217 nuclear and biochemical materials specialists from the Chinese military began work at the site on Thursday, the official Xinhua news agency said.
The explosions that rocked the city registered on earthquake scales and could be seen from satellites in space.
Yesterday, plumes of smoke from fires still burning could be seen rising from the devastated landscape of crumpled shipping containers, incinerated cars and burnt-out buildings. The fumes raised fears that the explosion had turned the air and water poisonous, especially after sodium cyanide was detected in the city's sewers on Thursday night. A forecast for rain heightened fears that the city's water supply might become contaminated.
Officials said the air remained safe to breathe. But many resident volunteers and even public security officers were seen wearing masks as they helped with various tasks, such as directing traffic and giving out bottled water.
Volunteer Wang Ning handed out ice cream outside a primary school, where those evacuated from their homes had been sheltered.
"It's better to be safe than sorry and to take the necessary precautions, since this is a fast-changing situation," he told The Straits Times. But retiree Tong Lishan, 61, said that he was satisfied with how the authorities had handled the situation so far.
For the past two days, he has been staying at the primary school for evacuated residents with his wife, Madam Chen Ling, 59.
"They've taken very good care of us. Everything that we need, such as our daily meals, has been very well provided," he told The Straits Times. Madam Chen added: "Whatever the situation, we believe the government will do its best to reduce the danger for us."