On 12 August 2015, a series of explosions at the Port of Tianjin in Tianjin, Northern China, killed 173 people, according to official reports, and injured hundreds of others. The explosions occurred at a container storage station in the Binhai New Area of Tianjin, China. The first two explosions occurred 33 seconds apart. The second explosion was much larger and involved the detonation of about 800 tonnes of ammonium nitrate (approx. 256 tonnes TNT equivalent). Fires caused by the initial explosions continued to burn uncontrolled throughout the weekend, resulting in eight additional explosions on 15 August.
The cause of the explosions was not immediately known, but an investigation concluded in February 2016 that an overheated container of dry nitrocellulose was the cause of the initial explosion. The official casualty report was 173 deaths (including eight missing), and 798 non-fatal injuries. Of the 173 fatalities, 104 were firefighters.
Background
Tianjin Dongjiang Port Ruihai International Logistics, or Ruihai Logistics, is a privately held logistics company established in 2011. It handled hazardous chemicals within the Port of Tianjin, such as flammable and corrosive substances, oxidizing agents, and toxic chemicals. The company, which employed 70, was designated by the Tianjin Maritime Safety Administration as an approved agent for handling these hazardous chemicals at the port, and its operating license was renewed two months prior to the explosions. Its 46,000-square-metre (500,000 sq ft) site, roughly the size of two city blocks, contained multiple warehouses for hazardous goods, a fire pump and a fire pond.
The warehouse building, owned by Ruihai Logistics, is recorded in a 2014 government document as being a hazardous chemical storage facility for calcium carbide, sodium nitrate, and potassium nitrate. Safety regulations requiring that public buildings and facilities should be at least 1 kilometre (0.62 mi) away were not followed, and local inhabitants were unaware of the danger. The authorities stated that poor record keeping, damage to the office facilities and "major discrepancies" with customs meant that they were unable to identify the substances stored. State media revealed that Ruihai had only received its authorisation to handle dangerous chemicals less than two months earlier, meaning that it had been operating illegally from October 2014, when its temporary license had expired, to June 2015.
Explosions
The first reports of a fire at a warehouse in the Binhai New Area began coming in at around 22:50 local time (14:50 UTC) on 12 August. The first responders were unable to keep the fire from spreading. Firefighters who first arrived on the scene proceeded to douse the fire with water as they were unaware that dangerous chemicals were stored on the site, thereby setting in motion a series of more violent chemical reactions.
At around 23:30 (15:30 UTC), the first explosion occurred and registered as a magnitude 2.3 earthquake, generating seismic shock-waves energetically equivalent to 2.9 tonnes of TNT. After 30 seconds, a second violent explosion occurred, causing most of the damage and injuries with shock-waves felt many kilometres away. The second explosion registered as a magnitude 2.9 earthquake and generated seismic shock-waves with energy equivalent to 21.9 tonnes of TNT. The resulting fireballs reached hundreds of meters in height. Around 23:40 (15:40 UTC) on 15 August, a series of eight smaller explosions occurred in the port as fire from the original blasts continued to spread. The total energy release was equivalent to 28 tonnes of TNT, or 100GJ.
The explosion was large enough to be photographed by Himawari, a geostationary meteorological satellite operated by the Japan Meteorological Agency (JMA). Chinese scientists subsequently estimated that the second more powerful explosion involved the detonation of about 800 tonnes of ammonium nitrate, based on crater size and lethality radius (336 tons TNT equivalent, based on relative effectiveness factor of 0.42).
One month after the explosion, official reports listed 173 deaths and 797 injuries. Media reported the area to be densely populated, with around 5,600 families living within 1.5 kilometres (0.93 mi) radius of the plant, the closest being only 520 metres (1,710 ft; 570 yd) away. Neither the developers nor the buyers were aware of the latent dangers of the activities at the nearby site, with developers also claiming to be victims. According to the Tianjin government, more than 700 people were injured by the explosion, many with extensive injuries, mostly from burns and explosive blast injuries. More than a thousand firefighters responded to the scene. A total of 104 were killed: 24 were firefighters from the China Fire Services branch of the People’s Armed Police, and 80 were volunteer firefighters. An additional five volunteer firefighters were presumed dead. One surviving firefighter from his team, a 19-year-old named Zhou Ti (周倜), was found on the morning of 14 August. The death toll, which also included 11 police officers, was the worst in a single incident for Chinese front line responders since the founding of the People's Republic of China in 1949.
Damage
Photographs and videos showed extensive destruction in and around the warehouse compound, with an enormous crater at the blast site. The buildings of seven more surrounding logistics companies were destroyed, and large quantities of intermodal container stacks were toppled and thrown by the forces of the explosions. More than eight thousand new cars from Hyundai, Kia, Volkswagen, Renault, and Toyota, parked in lots located near the blast site, were largely burned as a result of the initial explosions. Numerous buildings surrounding the blast site were declared "structurally unsafe". In total, 304 buildings, 12,428 cars, and 7,533 intermodal containers were damaged. Beyond insurance, the cost to businesses of the break in the supply chain caused by the explosions was estimated at $9 billion, making it the third most expensive supply chain disruption of 2015.
Apartment blocks 2 km (1.2 mi) from the site sustained shattered glass, loss of roof tiles and damage to ceilings – with 17,000 units being affected. Nearby Donghai Road Station suffered severe damage as a result of the explosions and was closed until 2016, as was the rest of Line 9 of the Tianjin Metro beginning on 13 August. A Japanese department store four kilometres (2.5 mi) away reported damage to walls and ceilings. The explosions also affected the National Supercomputing Center of Tianjin several kilometres away, knocking out windows and causing some internal ceilings to collapse; the center's supercomputer Tianhe-1A itself was not damaged.
Cause
It is not known what chemicals were being stored at the site. In addition to vast quantities of sodium cyanide and calcium carbide, paperwork was discovered showing that 800 tonnes of ammonium nitrate and 500 tonnes of potassium nitrate were at the blast site. On 17 August, the deputy director of the public security bureau's fire department told CCTV:
Over 40 kinds of hazardous chemicals [were stored on site]. As far as we know, there was ammonium nitrate and potassium nitrate. According to what we know so far, all together there should have been around 3,000 tonnes.
Ammonium nitrate, which is predominantly used as an agricultural fertilizer, oxidizing agent in explosive compositions, and in manufacturing of other chemicals, has been the cause of a number of other fatal industrial explosions. A fire department spokesman confirmed that firefighters had used water in combating the initial fire, which may have led to water being sprayed on calcium carbide, releasing the highly flammable gas acetylene. This would have provided the fuel source for reaction with the oxidizer, ammonium nitrate, thus triggering its detonation more readily.
Pollution
At least 700 tonnes of highly toxic sodium cyanide was stored at the site – 70 times the legal limit. Sodium cyanide leakage was reported in the sewer. On 13 August, sulphur dioxide, carbon monoxide and nitrogen oxides, all of which are toxic, were detected within 500 m (1,600 ft) of the origin of the explosion, but the levels conformed with the national standards. Gases were undetectable 2 km (1.2 mi) from the site during initial testing on 14 August.
When the first rains after the initial explosions arrived on 18 August, white chemical foam covered the streets. Citizens complained of burning sensations and rashes on sensitive skin regions after coming into contact with rain droplets. However, meteorologists and health experts sought to reassure the public that the rain was not directly harmful to health, whilst the Environment Protection Board advised against exposure to the rain due to traces of cyanide dust reacting with water.
Thousands of dead sticklebacks washed up on the banks 6 km (3.7 mi) from the explosion site on 20 August, fuelling fears of water contamination. Officials downplayed the fears, saying that there were not high levels of cyanide in the river and that the fish likely died due to oxygen depletion in the water.
More precipitation throughout August in the Binhai New Area brought more complaints of skin irritations and burns from volunteers and journalists. A bright white foam manifested yet again on the streets in a similar manner to before. Deng Xiaowen, director of Tianjin's environmental monitoring centre, stated that the foam was "a normal phenomenon when rain falls, and similar things have occurred before".
Victims
On Thursday morning, the Chinese leaders ordered officers in the city to make full effort in rescuing the injured, and search for those missing. Xi Jinping, the General Secretary of the Chinese Communist Party and Li Keqiang, the Premier of the People's Republic of China, instructed police to investigate the cause of the incident and punish those responsible for the blast.
Tianjin officials, concerned at the potential public response, announced initially that fourteen people had perished in the explosions, but later raised the death toll to forty-four once the scale of the explosions became clear. The South China Morning Post (SCMP) cited a Tianjin police source that officers had been instructed to remove bodies from the scene to deliberately understate the official death toll, which angered the Tianjin government.
The morning following the explosion, military personnel began to arrive in Tianjin to help with the search and recovery efforts. Extra equipment, such as bulldozers, were brought in to help with the clean-up operation. Over 200 nuclear and biochemical experts, including a team from the International Atomic Energy Agency, began arriving in Tianjin to assess the health risks from the chemicals being released into the atmosphere. Government personnel set up twelve temporary monitoring stations near the blast site with above-normal levels of pollutants being detected. A nearby drainage outlet was also closed, and water quality tested.
Firefighting was suspended on the afternoon of 13 August due to the uncertainty of the content and quantity of hazardous materials being stored on site. A team of over two hundred chemical specialists was deployed to assess the hazardous materials on site and dangers to the environment, and to determine the best way to put out the remaining fires and proceed with search and rescue and clean-up operations. Later that day, rescue personnel were dispatched in an attempt to remove the 700 tonnes of sodium cyanide believed to be stored at the site, with hydrogen peroxide being prepared to neutralise the chemicals. Daily press conferences were organised. A press conference organised by local officials held on 14 August came to an abrupt end when a journalist began asking questions as to why such dangerous chemicals were stockpiled so close to housing estates.
Initially, more than 3,500 area residents were staying in temporary shelters, but the number surpassed 6,000 within three days. The government issued an evacuation order over concerns of further explosions; not all residents complied.
On 15 August, local authorities ordered the evacuation of residents within a 3 km (1.9 mi) radius of the blast site, prompted by the threat of "toxic substances", including sodium cyanide.
The State Council ordered inspections of all businesses using dangerous chemicals and explosives across the country.