Mexico City, September 18 (teleSUR-RHC)-- Some 7.4 million people and 2.2 million homes in Mexico City are at high risk in case of a powerful earthquake, local officials said ahead of the 30th anniversary of the deadly quakes of September 19th and 20th which left over 10,000 people dead. Carlos Valdes, head of the National Center for Disaster Prevention (Conapred), said that 334 health centers and 5,210 schools are also at high risk, as they are located in the seismic zone 3, which has a very marshy underground. The official said that given these figures, the government needs to again urgently take measures and make efforts to strengthen the institutions in charge of disaster prevention and assistance. Valdez said that since the massive earthquakes of 1985 Mexico has been transformed and there has been progress in the construction sector, the installation of sensors and early alert systems. Mexico City and the surrounding metropolitan area makes for one of the most populated in the world with over 22 million inhabitants. The September 19th earthquake was reported to be about 8.4 magnitude, but the most dangerous aspect of the movement was that it lasted for about two minutes and the fact that it was trepidatory and oscillatory. Earthquakes are more commonly either one or the other, but when both movements come into play, it makes for more destruction, as both waves collide with each other. The government places the official death toll at 3,200, but those journalists who saw where the bodies were concentrated, say it was more like 10,000 and possibly 30,000. Over 30,000 buildings were completely destroyed, 68,000 others were partially damaged. At least 150,000 jobs were lost to the earthquake. On the evening of September 19th, about 12 hours after the quake, dump trucks full of bodies could be seen taking remains of victims to mass graves.