Here's what you should know about the unfolding Tianjin crisis

Blasts rocks northern Chinese city of Tianjin
china tianjin explosion ripley pkg_00020012

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Blasts rocks northern Chinese city of Tianjin 02:07

(CNN)Several blasts ripped through the Chinese port city of Tianjin late Wednesday, killing at least 85 and injuring more than 700.

Rescue efforts and an investigation are still underway but here are some key facts to help you understand the developing crisis:

Where is Tianjin?

    Tianjin is a coastal city of more than 13 million people situated in northeastern China. Just a half-hour train ride from Beijing, it's one of the four municipalities directly controlled by the central government alongside Shanghai, Chongqing and the nation's capital.
    Massive explosion reportedly injures 500 in China
    Massive explosion reportedly injures 500 in China

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      Massive explosion reportedly injures 500 in China

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    Massive explosion reportedly injures 500 in China 02:26
    Tianjin has long served as an important port since imperial times and has, at various points in history, been occupied by colonial powers. At one point, it was shared by nine countries: Italy, Germany, France, Russia, UK, Australia, Japan and Belgium. It's also known for being the setting of the Boxer Rebellion in 1900 when Tianjin residents violently revolted against foreign Christian missionaries.
    Today, its colonial past can be seen in the Italian Concession district, which features avenues with European-style architecture. Although by no means a small city, it is known for being much more relaxed than nearby Beijing and is often ranked high up on the list of most livable Chinese cities.

    When and where did the explosions take place?

    Reports say the explosions happened just before midnight, when most workers would not have been present. Although the impact has devastated parts of the city, and death and injury tolls are expected to rise, it could have been much deadlier.
    As CNN correspondent Will Ripley who is on the scene pointed out, it was also helped by the fact that it took place in the industrial center of Tianjin called the Binhai New Area, and not in a densely-populated residential neighborhood.
    China's Earthquake Networks Center said there were just under 90,000 people in a 5 km, or just over 3 mile, radius before the blast.
    The explosions took place outside Tianjin's downtown district in the eastern industrial zone.
    In December last year, Chinese Premier Li Keqiang appointed Tianjin as a new free trade zone, similar to the special economic areas seen in Shanghai and Shenzhen. Essentially, the government creates tax-breaks and other business incentives to attract investment from companies.
    The Binhai New Area industrial center is home to several hundred Fortune 500 companies which take advantage of Tianjin's status as a world-class shipping and logistics hub -- multinationals like Volkswagen, Renault, Airbus, Tishman Speyer, and Motorola have offices there.

    Chemical fire?

    The initial explosion took place at warehouse belonging to Tianjin Dongjiang Port Rui Hai International Logistics Co. Ltd, which state media said housed "dangerous chemicals."
    Officials have sent in a team of 217 military chemical experts to the city and rescuers are now trying to remove 700 tons of sodium cyanide, Xinhua reported.
    Video shows aftermath of Tianjin explosion, shockwave
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      Video shows aftermath of Tianjin explosion, shockwave

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    Video shows aftermath of Tianjin explosion, shockwave 02:20
    Although the exact cause has yet to be confirmed, Tianjin is close to major oil and gas deposits in the Bohai Bay basin and petrochemicals is a major industry.
    The China Earthquake Administration said the first explosion registered a magnitude of 2.3, while a second explosion was even stronger, measuring 2.9 -- the equivalent of 21 metric tons of TNT explosive.
    Photos and video have emerged showing incredible devastation from crumpled shipping containers thrown about and piled up and row upon row of incinerated cars. Survivors say they experienced the tremors as far away as 10 km -- approximately 6.2 miles.
    A day later and witnesses report a lingering and eye-stinging chemical odor in the air over half a mile away from the site of the explosions.