TIANJIN - A firefighter was pulled alive from the burnt-out wreckage of a warehouse in an industrial area in the northern Chinese port city of Tianjin on Friday, two days after twin explosions ripped through the area, unleashing a fireball that caused massive destruction spanning kilometres.
And amid mounting concerns over safety, Mr Gao Huaiyou, deputy director of Tianjin's work safety watchdog, told reporters on Friday that the blast site had been sealed to contain the toxic chemicals.
The authorities were, however, still unable to determine the dangerous chemicals at the storage facility where the explosions happened, or the cause of the blasts.
Mr Gao said this was due to discrepancies between the accounts of company management and the customs department, and because records in the company's office had been destroyed during the blasts.
The fiery blasts on Wednesday night killed at least 56 people, including 21 firefighters. Some 700 were injured, more than 70 seriously.
Some 1,000 firefighters were deployed to the site, including 19-year-old firefighter Zhou Ti, who was rescued from the wreckage on Friday.
He sustained chest injuries but was in a stable condition, the city government said on China's Twitter-like Sina Weibo.
Officials said Mr Zhou had no recollection of when he reached the scene, and it was not clear whether he was among the first responders to the site who were caught up in the giant blasts.
Residents living near the blast site are worried about their safety after the media reported that there could be hundreds of tonnes of dangerous chemicals at the site. A weather forecast of rain on Friday that could further contaminate water supplies has also raised alarm.
But Mr Gao said that any light rain was unlikely to cause much harm. Officials also maintained that their tests of harmful substances in the air showed that the level was still within safe limits.
Police in Tianjin said earlier that the warehouse was owned by Tianjin Dongjiang Port Ruihai International Logistics, a private firm licensed to handle hazardous cargo.
According to the official People's Daily, the firm's top official had been detained for questioning.
The newspaper also reported that the storage facility's construction clearly violated safety rules.
Under Chinese regulations, warehouses stocking dangerous materials must be at least 1km away from surrounding public buildings and main roads, it said, but there were facilities such as two residential compounds, two hospitals and several main roads within that distance.
"The warehouse should not have passed the environment assessment under normal circumstances," the paper quoted an unnamed environmental expert as saying.
Reuters, citing the Tianjin Maritime Safety Administration, reported that the firm violated packaging standards during a safety inspection two years ago.