Every time he passes the spot where his younger sister is buried, Tangshan resident Qin Boheng, 39, feels deep sorrow. Thirty years ago, his sister died in the devastating Tangshan earthquake that claimed 240,000 lives, almost a quarter of the city's population at the time.

Qin's memories of the disaster are of corpses and the putrid stench in the air. "Stories about that earthquake are too heavy to talk about," he said. "Every survivor has a heart-breaking memory."

On July 28, 1976, a 7.8-magnitude earthquake struck Tangshan in north China's Hebei Province. In about 15 seconds, the city known as a cradle of modern industry in China was almost entirely razed.

After the earthquake, some people feared Tangshan, about a two-hour drive east of Beijing, would be wiped off the map. Instead, the rebuilding began, and 30 years after the catastrophe Tangshan is a revitalized city, full of energy and hope.

But the earthquake of 1976 was largely unexpected and some residents and experts wonder: could it happen again? And if it did, would Tangshan be ready?

The rebuilding continues, in terms of both ensuring the city's structures are fortified to better handle future quakes and modernizing Tangshan's once-devastated local economy.

Economic reconstruction

Tangshan was once known as the coal capital of China, the birthplace of the country's first modern mine. In its prime, half of the city's population worked in the coalmines or related industries.

However, the earthquake of 1976 completely ruined this century-old industrial city. According to official statistics, the earthquake destroyed 97 percent of the factory buildings of mining enterprises and 56 percent of mining equipment, paralyzing Tangshan's core industry.

But not for long. According to records from the municipal government, only seven days after the earthquake, the first batch of bicycles was assembled in the city; 20 days after the disaster, a locomotive was produced; after 28 days, the first steel furnace was manufactured; and about six months after the earthquake, 666 of the city's 692 enterprises had resumed production.

Tangshan today has a population of nearly 3 million people. If not for the earthquake damage purposely left visible in some places as a reminder of what happened in 1976, few people would believe that this city had once been leveled.

"In my opinion, Tangshan's prosperity today should be attributed to the policy of reform and opening up, as well as the local people's hard work," said Xu Xiangbin, Director of the Tangshan Municipal Infor-mation Office.

According to information from the Tangshan Municipal Commission of Development and Reform, the city's GDP in 2005 reached 202.7 billion yuan, 3.6 times that in 1995, with its comprehensive economic strength ranking first among Hebei Province's 11 prefecture-level cities and surpassing that of Shijiazhuang, the provincial capital.

Nowadays Tangshan is at the crossroads of economic transition.

After the earthquake, Tangshan continued a resource-based model of development, relying completely on coal. "This industrial development model causes too much pollution and consumes too much energy, so it's unlikely to promote the city's development in the long run," said Hu Shining, chief of the industrial economy division of Tangshan Municipal Commission of Development and Reform.

Located on the north coast of Bohai Bay and having a coastline of 190 km, Tangshan was among the first coastal cities to be opened to the outside world. To tap the potential of its favorable location, the municipal government has proposed a strategic transitional concept: gearing to the sea and going to the outside world.

In 2003, construction of Caofeidian Industrial Park on the southern edge of the city began, a tangible step forward in terms of Tangshan's economic transition. This development zone possesses a deep-water port. At the end of 2005, two mineral ore wharves with a handling capacity of 250,000 tons each began operation, and negotiation is underway for the construction of a number of new international shipping wharves. The municipal government has set an ambitious goal to turn Caofeidian into the Rotterdam (the largest port city in the world) of north China. The development of Caofeidian is included in China's development plan for the next five years.

For the upcoming 30th anniversary of the Tangshan earthquake, the city has decided on the theme: Comfort the compatriots who died in the earthquake.

"I think economic development is the best way to comfort our compatriots who lost their lives to that earthquake," said Xu from the Information Office.

Is Tangshan safe?

Before the disaster of 1976, Tangshan wasn't considered to be at high risk for earthquakes. The seismic fortification of buildings in the city was only at level 6 (adequate for earthquakes below a magnitude of 5).

"Tangshan at that time was a defenseless city, and inadequate seismic preparation is the harshest lesson we learned from the catastrophic earthquake," said Li Baomin, deputy director general of the city's earthquake administration.

Li believes that if the earthquake happened today, there would be far fewer deaths. He points out that when the quake hit the city, the then Tangshan No.1 Flour Factory remained nearly intact. The reason is that the factory buildings were built according to a design by engineers outside Tangshan, with a seismic fortification level of 8 (equal to magnitude 6).

The disaster in Tangshan changed building safety standards around China. Professor Su Youpo, Director of the Center for Research on Earthquake Engineering of Hebei Province, said that following the earthquake, the China Earthquake Administration worked out and issued the Chinese seismic intensity zoning map (now called the ground motion parameter zoning map).

Based on the geological structures, site conditions and historical statistics of different regions, standards and requirements for earthquake fortification were proposed for the first time, helping to improve the overall fortification level of the country.

According to China's zoning map, the seismic fortification intensity around the country ranges from 6 to 9. Although intensity 9 (magnitude 7) is not a common standard, reaching a fortification intensity level of 8 is a goal in many places. For example, the standard in Tangshan has been raised from 6 to 8, the same as in Beijing.

The minimum level for quake fortification in Tangshan is intensity 8. "It is an iron principle," said Li of Tangshan's earthquake administration.

At the same time, laws and regulations on earthquake resistance have been put into effect. Professor Su said they are a direct result of the Tangshan earthquake in 1976.

Su, a native of the city, experienced the earthquake when he was 20 years old. While he managed to escape from the ruins, all four members in his elder sister's family died. Believing that earthquake tragedies are always indirectly caused by the destruction of buildings, Su chose to major in civil engineering, devoting himself to the study of earthquake resistance. After finishing his Ph.D, Su decided to stay in Tangshan despite having opportunities to work in major cities.

"My home is in Tangshan and my research work requires me to live in Tangshan," Su said.

Improving earthquake protection capability continues to be a priority in the development of Tangshan. According to Wang Xuchun, Deputy Director of the Tangshan Municipal Bureau of Urban Planning, after the big earthquake, the bureau carried out a geological safety evaluation for earthquakes in the city. Based on this work, the city is divided into four kinds of areas, namely, those that are suitable for construction, basically suitable for construction, basically unsuitable for construction and unsuitable for construction. The four areas are marked in different colors on the city's urban planning map.

"By doing this, we try to avoid those geologically dangerous areas, with a view to strengthening earthquake fortification," Wang said. Wang is also a survivor of the Tangshan earthquake, during which he saved himself by escaping from a window at the age of 10.

He explained that in order to improve the city's earthquake fortification, the construction of high-rise buildings is restricted, and most structures are five or six stories. As far as construction materials are concerned, brick houses of weak seismic fortification are forbidden, and most buildings in Tangshan are made of reinforced concrete. In places where people tend to gather, more greenbelts and open land have been included in the design, to act as temporary evacuation sites in case of future earthquakes.

Li Baomin revealed that Tangshan is planning to upgrade its earthquake fortification level to that adopted by more developed countries in the next five years, to help prevent human deaths, serious property losses or social turmoil if destructive earthquakes (magnitude 5 or higher) hit the city.

According to the municipal government, ensuring Tangshan is a safe place to live is a core development objective.

Yue Zhi, 61, experienced the earthquake of 1976 but said he has never thought of leaving Tangshan. "There is little chance of another big earthquake hitting Tangshan and I think our homes now are strong enough to resist earthquakes," he said.

While some Chinese people still consider Tangshan to be an unsafe place, Li argued otherwise. "Tangshan is the safest city in China of all the places of the same geological structure," he said.

The cost of protection

The Tangshan earthquake had a magnitude of 7.8 according to the Chinese Government, equal to an earthquake intensity of 11, but the present fortification level in Tangshan can at most help the city to withstand an earthquake with an intensity of 8. Calculated in accordance with the destructive force of earthquakes, the city's current fortification level just meets the minimum standard.

"While building earthquake-proof systems, the cost must be taken into consideration, and especially the economic input," Professor Su explained.

Su's office building has a special architectural design. In the basement, between the main structure and the basement, are dozens of round, black isolators, which divide the building into two parts, with all its weight resting on the isolators.

Each isolator is made of overlapping rubber and steel plates, with a thickness of 170 mm. Although they are small, the isolators are capable of relieving the building of 70 percent of the shakes caused by an earthquake. That is to say, if an earthquake pushes a force measuring 100 tons on the building, the isolators will help reduce it to a force measuring 30 tons.

According to Su, every year Tangshan is hit by at least one minor earthquake. His earthquake isolation building serves to a large extent as a base for experiments, equipped with devices that provide data about earthquakes.

Generally speaking, at most, earthquake isolation buildings are 50 meters in height. Brick-and-concrete construction costs 80 yuan more per square meter than ordinary construction, but the cost will not rise if the building is a 10-story or higher concrete construction. Although this type of structure has been widely constructed in other parts of China, Su's is the only earthquake isolation building in Tangshan, despite the city's tragic history.

"This problem is related to real estate developers. No developer wants to increase business costs," Su said. "A developer must be a kind-hearted man who will strive to ensure the buildings in his project meet the minimum standards of earthquake resistance."

Su said there is only a slight chance that an earthquake will occur, especially a large one, and if a building can stand a destructive earthquake (above magnitude 5), it is basically safe. Without special earthquake-proof facilities, houses will be cheaper, the developers may earn more profits and the government may collect more revenues. If features to help buildings withstand extremely destructive earthquakes are included in the design, developers and consumers have to pay more. If there are no powerful earthquakes, this is an unnecessary investment.

"As different interest groups see the problem from their own perspective, it's not easy to reach a balance between earthquake resistance and economic profits. But in the end, human life is most valuable of all," Su said.